| steely(adjective, determined, resolute, uncompromising, unshakeable) |
| stick |
| stick fast |
| stick it out(expression, idiom) |
| stickle |
| stiff-necked(adjective, determined, resolute, uncompromising, unshakeable) |
| strong-willed(adjective, determined, resolute, uncompromising, unshakeable) |
| stuffed shirt |
| take no denial(expression, idiom) |
| take the plunge(expression, idiom) |
| timid(moderate, cautious, conventional, traditional, conservative) |
| true-blue(adjective, honest, loyal, faithful, incorruptible) |
| unchangeable(moderate, cautious, conventional, timid, traditional) |
| unchanging(moderate, cautious, conventional, timid, traditional) |
| uncreative(moderate, cautious, conventional, timid, traditional) |
| undaring(moderate, cautious, conventional, timid, traditional) |
| unimaginative(moderate, cautious, conventional, timid, traditional) |
| unshakeable(adjective, determined, resolute, uncompromising) |
| unswerving(adjective, determined, resolute, uncompromising, unshakeable) |
| unwavering(adjective, determined, resolute, uncompromising, unshakeable) |