Green’s Dictionary of Slang

pusher n.

1. in commercial senses.

(a) [late 19C] (US) a salesman, often defined by occupation.

(b) [1900s-60s] (US tramp) the foreman on a construction site.

(c) [1900s] (US Und.) a bank teller; a cashier.

(d) [1910s] (Aus.) an outstanding example.

2. [1900s–40s] a young woman, esp. a flirt or a prostitute; see also square pusher

3. in Und. uses.

(a) [1900s] (Aus.) a petty thief or confidence trickster.

(b) [1920s+] (drugs, also pusherman) one who sells drugs; usu. in his ‘small-time’ or ‘retail’ role as opposed to the wholesale dealer n. (2)

(c) [1930s+] (US Und.) a distributor of counterfeit money.

(d) [1950s] (US gay) a man who runs a string of homosexual male prostitutes.

4. [1950s+] (Aus.) a pushchair.

5. [1980s+] (drugs) as an implement.

(a) a thin stick, typically a chopstick, used to pack a cocaine pipe.

(b) a metal hanger or umbrella rod used to scrape residue in crack cocaine stems.

In phrases

square pusher (n.) [square adj. (1)]

1. [late 19C–1930s] a young woman, usu. respectable; thus square-pushing, courting.

2. [1920s] a boyfriend.