| strapping |
| strenuous |
| strict(adjective, persistent, obstinate, insistent, dogged) |
| strong(tough, solid, determined, noble, bold) |
| substantial |
| tough(strong, solid, determined, noble, bold) |
| unconquerable(adjective, persistent, obstinate, insistent, dogged) |
| uncooperative(adjective, persistent, obstinate, insistent, dogged) |
| unflinching(adjective, persistent, obstinate, insistent, dogged) |
| ungovernable(adjective, persistent, obstinate, insistent, dogged) |
| unmanageable(adjective, persistent, obstinate, insistent, dogged) |
| unregenerate(adjective, persistent, obstinate, insistent, dogged) |
| unruly(adjective, persistent, obstinate, insistent, dogged) |
| venturous(strong, tough, noble, bold, resolute) |
| vigorous |
| warehouse |
| wayward(adjective, persistent, obstinate, insistent, dogged) |
| wrongheaded(adjective, persistent, obstinate, insistent, dogged) |
| abrupt |
| adamant(adjective, persistent, obstinate, insistent, dogged) |