Siceps Share definition Flag Noun - Used to describe pathetic arm muscles - whereby the muscles are so weak, they droop below the bone, like a swinging hammock. "Look at that pathetic loser, he's got a right set of Siceps!" Siceps by J0bey September 26, 2009 0 0 Get merch Get the Siceps mug. Buy Now β $32.95 See more merch