FL

Abbreviation with 7 meanings

FL
Stands for	Florida
Meanings	7
Categories	Geography & Places, Transportation & Travel, Medical, Texting & Internet Slang, Writing & Everyday, Science & Engineering
Also written	Fl, fl.

FL has seven meanings. The most common are Florida (US state) and Floor (address); it can also stand for Flight level, Follicular lymphoma, Female lead, Floruit (flourished) and Flerovium.

Meanings of FL at a glance

#	FL stands for	Context
1	Florida	Geography & Places › US State
2	Floor	Geography & Places › Address
3	Flight level	Transportation & Travel › Aviation
4	Follicular lymphoma	Medical › Hematology and Oncology
5	Female lead	Texting & Internet Slang › Fandom and Fan Fiction
6	Floruit (flourished)	Writing & Everyday › Latin
7	Flerovium	Science & Engineering › Chemical Element

1. Florida

Geography & Places · US State Abbreviations

Spain ceded Florida to the United States in 1821, and it became the 27th state on March 3, 1845. Tallahassee is the capital and Jacksonville the largest city, and the Sunshine State has the longest coastline in the contiguous US, roughly 1,350 miles.

Example: Snowbirds return to Naples, FL every November and stay through Easter.

In edited prose Florida becomes Fla., as in ORLANDO, Fla., or R-Fla. FL was part of the 1963 two-letter list. In address lines Fl or FL can also mean floor (Ste 400, Fl 4); position decides which is meant, because the state code always follows the city name.

2. Floor (Fl)

Geography & Places · Address Abbreviations

Shows the floor or story within a building, as in 100 Broad St Fl 12, especially when a company occupies a whole floor without a suite number.

Example: Reception is on Fl 22; take the express elevator.

FL is the USPS form and also Florida's postal code; position decides, since the state always follows the city. In British and European usage the ground floor is not counted, so the first floor is one level up from the street.

3. Flight level

Transportation & Travel · Aviation Abbreviations

Altitude expressed in hundreds of feet with the altimeter set to the standard pressure of 29.92 inches of mercury (1013.25 hectopascals), so FL350 is roughly 35,000 feet. Flight levels begin at 18,000 feet in the US, while in Europe the transition altitude varies by country and airport.

Example: Climb and maintain FL350, contact Kansas City Center on 132.45.

Using a common pressure setting at high altitude ensures all aircraft measure altitude the same way regardless of local weather. Pronounced "flight level three-five-zero." Because flight levels are pressure altitudes, an aircraft at FL200 in very cold air is noticeably lower than 20,000 feet in true altitude, which matters for terrain clearance over mountains.

4. Follicular lymphoma

Medical · Hematology and Oncology Abbreviations

Slow-growing (indolent) B-cell non-Hodgkin lymphoma, the second most common lymphoma, characterized by the t(14;18) translocation that switches on the BCL2 gene. It often presents with painless lymph node enlargement in middle-aged and older adults.

Example: Low-grade FL with low tumor burden, no symptoms: active surveillance with CT every 6 months.

Many patients with low tumor burden are observed without treatment for years, and early therapy has not been shown to improve survival in that group. Treatments include rituximab alone or with chemotherapy, and bispecific antibodies and CAR-T cells for relapsed disease. A minority transform into aggressive DLBCL over time. The disease is usually incurable but has a long natural history.

5. Female lead

Texting & Internet Slang · Fandom and Fan Fiction Abbreviations

Main female character in a drama, webtoon or novel, especially in East Asian dramas and web novels, where fans discuss her choices and development.

Example: Finally an FL who isn't clumsy and actually runs her own company.

Counterpart to ML (male lead). Webnovel readers often seek out stories with a "smart FL" or "OP FL" (overpowered female lead). Also the US postal code for Florida.

6. Floruit (flourished) (fl.)

Writing & Everyday · Latin Abbreviations

Gives the period when a person was known to be active, used when birth and death dates are unknown. Encyclopedias, art catalogs and histories apply it chiefly to ancient, medieval and obscure figures.

Example: The poet Sappho (fl. c. 600 BC) wrote lyrics of which only fragments survive.

Floruit is the third-person singular perfect of Latin florere, "to flower." It often combines with circa or a date range, as in fl. 1340-1360, and older works write flor. or fl without a period. It differs from b. and d. because it records documented activity, not a life span, so the person may have lived decades beyond the dates given.

7. Flerovium (Fl)

Science & Engineering · Chemical Element Abbreviations

Flerovium (atomic number 114) is a superheavy element in group 14, below lead, first reported by the Joint Institute for Nuclear Research in Dubna with Lawrence Livermore National Laboratory around 1998-1999. Its relatively long-lived isotopes supported predictions of an "island of stability" for superheavy nuclei.

Example: Experiments suggest that Fl may be a volatile metal, chemically less reactive than lead.

The name, approved in 2012 together with livermorium, honors the Flerov Laboratory of Nuclear Reactions in Dubna, itself named after Soviet physicist Georgy Flyorov. Flyorov is also known for writing to Stalin in 1942 urging the Soviet Union to pursue an atomic bomb. The placeholder name before 2012 was ununquadium (Uuq).

More US state abbreviations

CO – Colorado
CT – Connecticut
DC – District of Columbia
DE – Delaware
GA – Georgia
HI – Hawaii
IA – Iowa
ID – Idaho

See all 51 US state abbreviations →

More address abbreviations

Dr – Drive
Est – Estate
Expy – Expressway
ext. – Extension
Fld – Field
Fls – Falls
Flt – Flat
FM – Farm to Market Road

See all 118 address abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.

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

FL