Green’s Dictionary of Slang

(W.I.) a womanizer, a sexual athlete.

1980		in Cassidy & LePage Dict. Jam. Eng. (2nd edn).
2000		(con. 1960s) T. White Catch a Fire 181: Rita’s flirtations with Peter continued, although she was wary of his reputation as a ‘Lash LaRue’ (oversexed playboy).