Someone who deliberately goes onto one of their friends, list of friends, and befriends all of the ones whom which they have no acquaintance.
Fb User 1: "Dude, stop Facebook mooching all my friends."

Fb User 2: "I don't know what your talking about..."

Fb User 1: "You added my uncle?"

Fb User 2: "uhh..I met him at camp."

Fb User 1: "He's 43 you Facebook Moocher!"
by iG SPYD3R September 23, 2010
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