Green’s Dictionary of Slang

log n.

[visual or fig. uses of SE log]

1. [mid-19C+] a stupid person.

2. the chin.

3. [1930s–50s] (US drugs, also log stick) an opium pipe.

4. [1930s+] a piece of excrement.

5. [1950s] (Aus.) a large person.

6. [1960s] (US) a bar counter [the wood from which it is constructed].

7. [1960s+] (US) the penis.

8. (US drugs) a marijuana cigarette.

9. [1970s+] (US drugs) phencyclidine [? sense 2].

10. [2000s] an erection.

In compounds

log stick (n.)

see sense 3 above.

In phrases

flog the log (v.) (also slog the log)

[1970s+] to masturbate.

go up a (hollow) log (v.) [the activity of a snake or lizard]

[1910s+] (Aus.) to hide.

log of wood (n.)

[mid-19C+] (Aus.) a dull, stupid person; thus log of ebony, a stupid black person.

sink the log (v.)

see under sink v.