| Verb | 1. | harden - become hard or harder; "The wax hardened"change - undergo a change; become different in essence; losing one's or its original nature; "She changed completely as she grew older"; "The weather changed last night" callus - form a callus or calluses; "His foot callused" harden, indurate - make hard or harder; "The cold hardened the butter" calcify - become impregnated with calcium salts cure - make (substances) hard and improve their usability; "cure resin" soften - become soft or softer; "The bread will soften if you pour some liquid on it" | |
| 2. | harden - make hard or harder; "The cold hardened the butter"change - undergo a change; become different in essence; losing one's or its original nature; "She changed completely as she grew older"; "The weather changed last night" callus - cause a callus to form on; "The long march had callused his feet" soften - make soft or softer; "This liquid will soften your laundry" | |
| 3. | harden - harden by reheating and cooling in oil; "temper steel"modify - make less severe or harsh or extreme; "please modify this letter to make it more polite"; "he modified his views on same-gender marriage" | |
| 4. | harden - make fit; "This trip will season even the hardiest traveller"toughen - make tough or tougher; "This experience will toughen her" | |
| 5. | harden - cause to accept or become hardened to; habituate; "He was inured to the cold"accustom, habituate - make psychologically or physically used (to something); "She became habituated to the background music" | |