lacking in strength or firmness or resilience; "flaccid muscles"; "took his lax hand in hers"; "gave a limp handshake"; "a limp gesture as if waving away all desire to know" G.K.Chesterton; "a slack grip"
being weak, relaxed, soft, and flabby. When muscles are flaccid, it means that their normal tone (tension) is decreased. Thus, the muscles will appear weak, relaxed, soft, and flabby. A flaccid state can be caused by a prolonged loss of breathing, so that oxygen is not brought into the body and carbon dioxide is not brought out of the body.