| nonstop(adjective, smooth, right, solid, level) |
| plodding(adjective, strong, firm, determined, steady) |
| plugging(adjective, strong, firm, determined, steady) |
| precise(adjective, close, correct, true, realistic) |
| predictable(consistent, steadfast, dependable) |
| punctilious(thorough, conscientious) |
| rectilineal |
| remorseless(adjective, determined, resolute, uncompromising, unshakeable) |
| rigorous(thorough, conscientious) |
| settled(adjective, firm, sensible, solid, steady) |
| straightaway(adjective, direct, right, true, straight) |
| through(adjective, smooth, right, solid, level) |
| trustworthy(adjective, close, correct, firm, honest) |
| unbroken(adjective, complete, smooth, right, total) |
| unchangeable(adjective, firm, solid, stable, fixed) |
| unconquerable |
| undrooping |
| unflappable |
| uniform(adjective, firm, solid, stable, fixed) |
| uninterrupted(adjective, smooth, right, solid, level) |