| adhesive(adjective, secure, tough, thick, tacky) |
| clinging(adjective, strong, free, firm, resolute) |
| diligent(adjective, precise, resolute, thorough, meticulous) |
| headstrong(adjective, tough, firm, resist, awkward) |
| immovable(adjective, strong, secure, firm, solid) |
| indomitable(adjective, strong, tough, firm, difficult) |
| purposeful(adjective, strong, firm, determined, serious) |
| sturdy(adjective, strong, sound, tough, fit) |
| unflinching(adjective, strong, flat, firm, determined) |
| untiring(adjective, determined, persevering) |
| fast(adjective, strong, free, secure, tough) |
| inexorable(adjective, tough, firm, determined, resolute) |
| pigheaded(adjective, tough, firm, difficult, resist) |
| unrelenting(adjective, determined, resolute, obstinate, uncompromising) |
| unswerving(adjective, strong, firm, determined, steady) |
| coherent(adjective, strong, unyielding) |
| contrary(adjective, difficult, wild, determined, awkward) |
| hardheaded(adjective, tough, firm, resist, determined) |
| single-minded(adjective, tough, intense, deliberate, determined) |
| spunky(adjective, strong, resolute, unyielding) |