Australian colloquial slang term Part dance-move, part seduction technique, the mudcrab involves the protagonist sidling up to unsuspecting members of the opposite sex (optional) on the dance floor, and without wasting time formally introducing themselves or initiating a civilised conversation, proceeds to bump and/or grind against them. This is generally to the dismay of the victim, unless performed during the optimal period for the manouevre, between the hours of 1 and 3am.

1) Noun; someone that struggles/fails at life, someone that can't do anything well.

2) Adjective; describing the poor efforts of an action.