lb

Etymology
From.

Symbol

 * 1)  Binary logarithm; logarithm to the base 2.
 * $$\mathrm{lb}(x) = \log_{2}(x)$$. $$ \mathrm{lb}(2) = 1 $$

Usage notes
The ISO 80000-2:2019 standard prescribes this symbol for the binary logarithm.

Derived terms

 * ft-lb
 * The struck-through abbreviation ℔ simplified to the pound sign (octothorpe) #.
 * lbf

Etymology 2
Abbreviation

Noun

 * 1)  leg bye