Green’s Dictionary of Slang

swinging adj.2

[SE swing + swing v. (8)]
[1950s+] (orig. US)

1. uninhibited, lively, fashionable; esp. in phrs. swinging London, swinging ’60s.

2. a general term of approval.

3. pertaining to drug use and culture.

4. aware, ‘on the ball’.

SE in slang uses

In compounds

swinging dick (n.) (also swinging Richard) [SE swinging + dick n.1 (5). Popularized in Tom Wolfe’s novel Bonfire of the Vanities (1987) where big swinging dicks was used to characterize the most successful of Wall Street’s financial wheeler-dealers] [1970s+] (US)

1. a person; usu. in phr. every swinging dick; thus phr. swing a big dick, to be influential.

2. an aggressive person.