1. p.n., (“smee’ uh goal”) in The Lord of the Rings, the proper name of Gollum, the stunted hobbit-like creature who seeks to regain the One Ring through guile and trickery.
2. in gamerese, pejorative term for a gamer who tries to be sneaky or pull a fast one. Ex: Good work, Sméagol, now the King’s pissed off!
Addendum: How about some etymology, from Ruth S. Noel’s The Languages of Middle Earth? Sméagol; from OE smeah “penetrating,” “creeping” (Smaug and smial are both related words). Déagol; from OE déagol “secret,” “unknown.” Déagol was Sméagol’s friend, who found the One Ring; Sméagol killed Déagol for it. An “unconfirmed source” indicates that Sméagol and Déagol were Old English titles for the Biblical Caine and Abel.