| unswerving(adjective, set, strong, tough, firm) |
| untiring(adjective, quiet, understanding, gentle, energetic) |
| resolved(adjective, strong, flat, firm, certain) |
| industrious(adjective, keen, difficult, intense, energetic) |
| loyal(adjective, strong, firm, determined, bold) |
| relentless(adjective, strong, tough, firm, determined) |
| sedulous(adjective, thorough, meticulous, painstaking, assiduous) |
| unflinching(adjective, strong, flat, firm, certain) |
| continuing(verb, adjective, strong, firm, determined) |
| patient(adjective, strong, firm, energetic, endure) |
| pertinacious(adjective, strong, tough, firm, determined) |
| staunch(adjective, strong, tough, flat, firm) |
| dedicated(adjective, strong, firm, determined, steady) |
| devoted(adjective, strong, firm, determined, steady) |
| earnest(adjective, careful, serious, resolute, persistent) |
| insistent(adjective, resolute, demanding, tenacious) |
| lasting(verb, adjective, abiding) |
| purposeful(adjective, strong, tough, keen, firm) |
| set(adjective, strong, tough, flat, firm) |
| single-minded(adjective, tough, firm, determined, unreasonable) |