Lamer is a jargon or slang name originally applied in cracker and phreaker culture to someone who did not really understand what they were doing. Today it is also loosely applied by IRC, BBS, demosceners, and online gaming users to anyone perceived to be contemptible. In general, the term has come to describe someone who is willfully ignorant of how things work. It is derived from the word "lame".

A lamer is sometimes understood to be the antithesis of a hacker. While a hacker strives to understand the mechanisms behind what they use, even when such extended knowledge would have no practical value, a lamer only cares to learn the bare minimum necessary to operate the device in the way originally intended.