DL

Abbreviation with 8 meanings

DL
Stands forDelta Air Lines
Meanings8
CategoriesTransportation & Travel, Units & Measurements, Technology & Computing, Sports, Medical, Writing & Everyday, Geography & Places
Also writtenDl, dL

DL has eight meanings. The most common are Delta Air Lines (airline code) and Driver's license (driving); it can also stand for Deciliter, Deep learning, Defensive line, Direct laryngoscopy and Distribution list, plus 1 more listed below.

Meanings of DL at a glance

#DL stands forContext
1Delta Air LinesTransportation & Travel › Airline Code
2Driver's licenseTransportation & Travel › Driving
3DeciliterUnits & Measurements › Metric and SI Unit
4Deep learningTechnology & Computing › Artificial Intelligence
5Defensive lineSports › American Football
6Direct laryngoscopyMedical › Anesthesia
7Distribution listWriting & Everyday › Email and Office
8DaleGeography & Places › Address

1. Delta Air Lines

Transportation & Travel · Airline Code Abbreviations

Atlanta-based US airline with its largest hub at Hartsfield-Jackson and other hubs in Detroit, Minneapolis-Saint Paul, Salt Lake City, New York, Boston, Los Angeles and Seattle. Delta co-founded the SkyTeam alliance in 2000.

Example: My DL 2384 connection in Detroit is tight, so I asked the gate agent for a seat near the front.

ICAO code DAL; callsign "Delta." Founded in 1925 as Huff Daland Dusters, a crop-dusting company in Georgia and later Louisiana, which makes it one of the oldest US airlines. Its 2008 merger with Northwest Airlines created what was then the world's largest airline. Delta is often rated the most punctual of the large US carriers.

2. Driver's license

Transportation & Travel · Driving Abbreviations

Official document allowing a person to drive motor vehicles on public roads, issued in the US by the state of residence. The abbreviation appears on forms, ID checks and the license itself, often beside the license number.

Example: Enter your DL number and state exactly as shown on your license.

Spelled "licence" in British English. US licenses also serve as the main form of identification for most adults. Each state sets its own testing, age and renewal rules, though federal law sets standards for REAL ID and commercial licenses. In Canada, licenses are issued by provinces.

3. Deciliter (dL)

Units & Measurements · Metric and SI Unit Abbreviations

One tenth of a liter, 100 mL. In the United States it appears mainly in blood test units such as mg/dL for glucose and cholesterol and g/dL for hemoglobin; in Scandinavian recipes it is an everyday kitchen measure.

Example: Fasting glucose was 104 mg/dL, slightly above the normal range.

To convert glucose from mg/dL to mmol/L, divide by 18; for cholesterol, divide by about 38.7. Swedish and Finnish cooks use measuring cups marked in deciliters for flour, oats and milk. Also written dl.

4. Deep learning

Technology & Computing · Artificial Intelligence Abbreviations

A subset of machine learning that uses neural networks with many layers to learn features directly from raw data such as pixels, audio and text. It powers modern image recognition, speech recognition, machine translation and large language models.

Example: Switching from hand-built features to a DL model improved defect detection on the assembly line.

The breakthrough came in 2012, when the AlexNet network from Geoffrey Hinton's group at the University of Toronto won the ImageNet competition by a wide margin using GPUs. Hinton, Yoshua Bengio and Yann LeCun shared the 2018 Turing Award for deep learning, and Hinton received the 2024 Nobel Prize in Physics with John Hopfield. Popular frameworks include PyTorch, TensorFlow and JAX. Elsewhere DL abbreviates "download" or "driver's license".

5. Defensive line

Sports · American Football Abbreviations

Front-line defenders who line up opposite the offensive line: defensive ends, defensive tackles and, in some schemes, a nose tackle. The DL tries to stop runs at the line of scrimmage and pressure the quarterback.

Example: The DL combined for six sacks and held the league's top rusher to 38 yards.

Also written D-line. Defensive linemen are described by "technique" numbers, such as 3-technique or 5-technique, that indicate where they line up relative to blockers. A 4-3 defense uses four linemen and three linebackers; a 3-4 uses three and four. DL can also mean a single defensive lineman.

6. Direct laryngoscopy

Medical · Anesthesia Abbreviations

Intubation technique in which the operator views the vocal cords along a direct line of sight using a laryngoscope with a Macintosh or Miller blade. The view is graded on the Cormack-Lehane scale from grade 1 (full view of the glottis) to grade 4 (neither glottis nor epiglottis visible).

Example: DL with Mac 3: Cormack-Lehane grade 3; switched to video laryngoscope.

Cormack and Lehane published their grading system in 1984. Direct laryngoscopy remains a core skill even as video laryngoscopy spreads, because blood, secretions or device failure can make a video screen useless. Notes often record the number of DL attempts.

7. Distribution list

Writing & Everyday · Email and Office Abbreviations

Refers to a single email address that forwards messages to a group of people, such as a team, department or project. Using a DL saves listing every member and keeps membership managed centrally.

Example: Please send the weekly report to the finance DL rather than to individual managers.

Microsoft Exchange and Outlook call these distribution groups or contact groups. Mailing lists differ in that members can usually subscribe themselves. Outside office email, DL can mean "download," a US driver's license or, in slang, "on the down-low," so context tells them apart.

8. Dale (Dl)

Geography & Places · Address Abbreviations

Valley, from Old English dæl, found in suburban street names and in British place names such as the Yorkshire Dales. USPS abbreviates it DL.

Example: Their mailing address is 7 Fern Dl, Hidden Valley.

In lowercase dl or dL means decilitre, and DL also abbreviates driver's license and download.

More airline code abbreviations

  • CI – China Airlines
  • CM – Copa Airlines
  • CX – Cathay Pacific
  • CZ – China Southern Airlines
  • EI – Aer Lingus
  • EK – Emirates
  • ET – Ethiopian Airlines
  • EY – Etihad Airways

See all 60 airline code abbreviations →

More driving abbreviations

  • CMV – Commercial motor vehicle
  • CR – County Road
  • CSA – Compliance, Safety, Accountability
  • DDS – Department of Driver Services
  • DMV – Department of Motor Vehicles
  • DOL – Department of Licensing
  • DPS – Department of Public Safety
  • DVLA – Driver and Vehicle Licensing Agency

See all 54 driving abbreviations →

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.