WordNet sense 1 (turned or twisted toward one side):

askew, awry, cockeyed, lopsided, skew-whiff

WordNet sense 2 (having or marked by bends or angles; not straight or aligned):

crooked, crooked

WordNet sense 3 (inclined to shake as from weakness or defect):

rickety, shaky, wobbly

WordNet sense 4 (lacking stability or fixity or firmness):

unstable