Source : WordNet®

toehold
     n 1: 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"
     2: a small foothold used in climbing
     3: a wrestling hold in which the toe is held and the leg is
        twisted against the joints