1. as a projectile.
(a) [18C+] a bullet.
(b) [1930s] a shell.
2. in senses of drink and drugs.
(a) [mid-18C] a fiery drink.
(b) [mid-18C+] a portion or measure of liquor.
(c) [1940s+] a portion (e.g. a sip, a cupful) of a non-alcoholic drink, e.g. coffee.
(d) [1950s] in non-alcoholic contexts, a portion, a share.
(e) [1960s] a portion or measure of a drug.
3. as a coin or token.
(a) [mid-19C+] (US) $1; thus half a slug, fifty cents; thus money, irrespective of amount.
(b) [1910s+] a token.
[1930s] to shoot.
[late 18C–early 19C] to drink a dram.