edge

ginger, punch, spice, tang

raucousness, severeness, severity, shrillness, virulence, vitriol

cattiness, maliciousness

pointedness, thorniness

ambit

brink, crest, curb, cusp, lip

ceiling, maximum

demarcation, extent, limitation, measure, mere, restriction, termination

borderland, frontier, march, outskirts, pale, selvage

lap

shore

allowance, head start, lead, leg up, margin, odds, start

ascendancy (also ascendency), command, dominance, mastery, predominance, superiority, supremacy, transcendence, transcendency

precedence, preference, prerogative, privilege, seniority

break, foothold, opportunity

benefit, blessing, boon, felicity, godsend, manna, windfall

ability, capability, capacity

potency, puissance, strength

nick

file

hem, trim

circumscribe, define, delineate, demarcate, outline, silhouette, sketch, trace

circle, compass, encircle, enclose (also inclose), environ, girdle, girth, loop, ring, round, surround, wall

check, confine, control, curb, limit, restrain, restrict