- flaccid, lax, limp, slack - 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"
Antonym: strong (indirect, via weak)
- flabby, flaccid - lacking firmness or stiffness; "flabby around the middle"; "flaccid cheeks"
Antonym: hard (indirect, via soft)