1. [late 17C+] cunning, on the lookout for oneself.
2. [18C+] intelligent, perceptive.
3. [1910s+] of a woman, attractive.
4. [1920s+] fashionable, good, admirable.
5. [1940s+] good (of quality).
6. [1940s+] used of a person who dresses well and with style, e.g. sharp dresser.
7. [1940s+] (S.Afr.) good (of health).
8. [1950s] (US drugs) intoxicated by a given drug.
9. [1960s] (S.Afr.) promiscuous.
[mid-19C] a policeman.
see under tool n.1
[1940s] (Aus.) extra-conscientious.
[1970s+] (US black) very smartly and fashionably dressed.
[1930s+] (US) to dress up smartly.
[20C+] a mocking phr. directed at someone who seems to think themselves exceptionally clever, well-informed etc..