| undying |
| unequivocal(adjective, set, clear, firm, total) |
| unflagging |
| unflappable |
| unflinching(adjective, strong, flat, certain, determined) |
| unlimited(adjective, complete, total, certain, definite) |
| unmodifiable(adjective, firm, certain, limited, definite) |
| unmovable(adjective, intense, certain, limited, definite) |
| unrelenting |
| unreserved(adjective, complete, warm, total, passionate) |
| unrestrained(adjective, complete, total, definite, absolute) |
| unrestricted(adjective, complete, total, definite, absolute) |
| unshakable(adjective, clear, strong, firm, solid) |
| unshaken(adjective, set, clear, strong, flat) |
| unswerving(adjective, set, firm, total, solid) |
| unvarying(adjective, set, clear, firm, solid) |
| unyielding(adjective, strong, flat, intense, determined) |
| valid(adjective, clear, certain, definite, positive) |
| without reservation(expression, adjective, complete, total, definite) |
| accurate(certain, unquestionable, undisputable) |