lb
Abbreviation with 7 meanings
| Stands for | Pound (avoirdupois) |
|---|---|
| Meanings | 7 |
| Categories | Units & Measurements, Sports, Geography & Places, Science & Engineering, Technology & Computing |
| Also written | LB |
lb has seven meanings. The most common are Pound (avoirdupois) (US customary and imperial unit) and Linebacker (American football); it can also stand for Lebanon, Lysogeny broth, Load balancer, Left back and Binary logarithm.
Meanings of lb at a glance
| # | lb stands for | Context |
|---|---|---|
| 1 | Pound (avoirdupois) | Units & Measurements › US Customary and Imperial Unit |
| 2 | Linebacker | Sports › American Football |
| 3 | Lebanon | Geography & Places › Country Code |
| 4 | Lysogeny broth | Science & Engineering › Biology |
| 5 | Load balancer | Technology & Computing › Cloud Computing |
| 6 | Left back | Sports › Soccer (Association Football) |
| 7 | Binary logarithm | Units & Measurements › Math |
1. Pound (avoirdupois)
Units & Measurements · US Customary and Imperial Unit Abbreviations
The standard unit of weight in the United States, 16 ounces, defined since 1959 as exactly 0.45359237 kilogram. Body weight, groceries, freight and gym equipment are measured in pounds.
Example: Maximum checked bag weight is 50 lb on most domestic flights.
The abbreviation comes from Latin libra pondo, "a pound by weight", which is also the source of the £ sign for the British pound sterling. In technical writing the symbol lb is used for both singular and plural; lbs is informal. The # sign is sometimes used for pounds in the US, as in a 5# bag of flour.
2. Linebacker (LB)
Sports · American Football Abbreviations
Defensive player who lines up behind the defensive line and in front of the defensive backs, responsible for stopping the run, covering backs and tight ends, and blitzing the quarterback. Most defenses use two to four linebackers.
Example: The LB led the team with 12 tackles and broke up a pass on third down.
Playbooks often name the middle linebacker "Mike", with "Sam" (strong side) and "Will" (weak side) for the outside linebackers. Great linebackers include Dick Butkus, Lawrence Taylor and Ray Lewis. In soccer LB means left back, a defender.
3. Lebanon (LB)
Geography & Places · Country Code Abbreviations
Lebanon, with Beirut as its capital and LBN as its alpha-3 code, has a cedar tree on its flag. Its political system divides top offices among religious communities under the 1943 National Pact.
Example: Remittances to LB rose after the 2019 banking collapse froze local deposits.
The language code lb means Luxembourgish, not Lebanese. LB also abbreviates pound (lb) and linebacker.
4. Lysogeny broth (LB)
Science & Engineering · Biology Abbreviations
Nutrient-rich growth medium of tryptone, yeast extract and sodium chloride, the standard liquid and agar medium for growing E. coli in molecular biology. Antibiotics are added to LB plates to select bacteria carrying a plasmid with a resistance gene.
Example: Pick a single colony into 5 mL of LB with ampicillin and grow overnight at 37 °C.
Giuseppe Bertani published the recipe in 1951 for studying lysogeny in bacteriophages; he later said LB stood for lysogeny broth, although it is widely, and incorrectly, expanded as Luria-Bertani or Luria broth. Common variants differ in salt concentration (Miller, Lennox and Luria).
5. Load balancer (LB)
Technology & Computing · Cloud Computing Abbreviations
A device or service that distributes incoming requests across multiple servers, improving capacity and availability and removing unhealthy servers from rotation through health checks. NGINX, HAProxy, F5 appliances and cloud services such as AWS ELB are examples.
Example: Put the new nodes behind the LB and drain the old ones before shutdown.
Layer 4 balancers route by IP address and port, while layer 7 balancers understand HTTP and can route by path, header or cookie. Common algorithms include round robin, least connections and consistent hashing. In weights, lb abbreviates pound, from the Latin libra.
6. Left back (LB)
Sports · Soccer (Association Football) Abbreviations
Defender on the left side of a back four, responsible for marking right wingers and overlapping in attack to deliver crosses. Left backs are often left-footed.
Example: Lineup note: the 19-year-old starts at LB with the regular sidelined by a hamstring injury.
Full-backs have become key attacking outlets; Roberto Carlos and Paolo Maldini are classic left backs from different eras. "Inverted" full-backs move into midfield in possession. In American football LB means linebacker.
7. Binary logarithm
Units & Measurements · Math Abbreviations
ISO 80000-2 symbol for the logarithm to base 2, so lb 8 = 3. It measures information in bits and counts how many doublings reach a value.
Example: A 1,024-entry table needs lb 1024 = 10 bits per index.
In practice log₂ and lg are more common than lb, which is easily confused with the abbreviation for pound. The binary logarithm counts the halving steps in binary search and the depth of a balanced binary tree.
Related abbreviations
More US customary and imperial unit abbreviations
- gr – Grain
- hh – Hands high
- imp – Imperial
- in – Inch
- lbs – Pounds
- LF – Linear foot
- mi – Mile
- mil – Mil (thousandth of an inch)
See all 43 US customary and imperial unit abbreviations →