| shamefaced(adjective, modest, nervous, humble, hesitant) |
| sheepish(adjective, quiet, simple, modest, nervous) |
| shrinking(adjective, gentle, modest, nervous, humble) |
| skeptical(adjective, uncertain, nervous, doubtful, hesitant) |
| skittish(adjective, modest, nervous, humble, shy) |
| suspect(uncertain, doubtful, unsure) |
| suspicious(adjective, uncertain, modest, nervous, humble) |
| suss(adjective, unreliable, insecure, treacherous, incalculable) |
| timorous(nervous, shy, meek, fearful, timid) |
| touch and go(expression, adjective, idiom, uncertain, nervous) |
| tricky(adjective, false, careless, loose, dishonest) |
| troubled(uncertain, nervous, insecure, unsure, self-doubting) |
| troublesome(adjective, unreliable, insecure, treacherous, incalculable) |
| truthless(adjective, unreliable, insecure, treacherous, incalculable) |
| two-timing(adjective, false, dishonest, deceitful, unreliable) |
| unassuming(quiet, modest, affected, meek, timid) |
| unclear(adjective, uncertain, nervous, doubtful, hesitant) |
| unconvinced(adjective, uncertain, nervous, doubtful, hesitant) |
| undecided(uncertain, nervous, doubtful, insecure, unsure) |
| uneager(adjective, modest, nervous, humble, hesitant) |