| make callous(verb, expression, dull, develop, rough) |
| numb(verb, dull, develop, rough, adjust) |
| paralyze(verb, dull, develop, rough, adjust) |
| render insensitive(verb, expression, dull, develop, rough) |
| roughen(verb, dull, develop, rough, adjust) |
| season(verb, dull, develop, rough, prepare) |
| steel(verb, dull, develop, rough, prepare) |
| stiffen(verb, dull, develop, rough, adjust) |
| strengthen(verb, dull, develop, rough, adjust) |
| stun(verb, dull, develop, rough, adjust) |
| stupefy(verb, dull, develop, rough, adjust) |
| teach(verb, dull, develop, rough, adjust) |
| toughen(verb, rough, prepare, adjust, strengthen) |
| train(verb, dull, develop, rough, prepare) |
| callus(verb, dull, develop, rough, adjust) |
| abrade |
| acculture(verb, adjust, adapt, accustom, adapted) |
| adapted(verb, adjust, adapt, accustom, acclimate) |
| anneal(verb, prepare, strengthen, harden, qualify) |
| beef up(expression, strengthen, harden) |