NOUN (3)

1. a relatively insignificant position from which future progress might be made;
- Example: "American diplomacy provided a toehold on which to proceed toward peace talks"
- Example: "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;

WordNet (r) 3.0 (2006):

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

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "toehold":
   advantage, bear hug, bite, clamp, clasp, clench, clinch, cling,
   clinging, clutch, death grip, embrace, firm hold, foothold,
   footing, footplate, footrail, footrest, full nelson, grapple,
   grasp, grip, gripe, half nelson, hold, hug, iron grip, lock,
   locus standi, nip, perch, purchase, quarter nelson, scissors,
   seizure, stance, stand, standing, standing place, stranglehold,
   tight grip, traction