a wrestling hold in which the toe is held and the leg is twisted against the joints
a small foothold used in climbing
a relatively insignificant position from which future progress might be made; "American diplomacy provided a toehold on which to proceed toward peace talks"; "his father gave him a toehold in the oil business"
based on custom rather than documentation; "an unwritten law"; "rites...so ancient that they well might have had their unwritten origins in Aurignacian times"- J.L.T.C.Spence