| queasiness(noun, upset, anxiety, doubt, nervousness) |
| red flag(expression, idiom) |
| red light(expression, idiom) |
| regard(noun, verb, trouble, disturb, worry) |
| restlessness(noun, upset, worry, concern, strain) |
| scare the daylights out of(verb, idiom, worry, agitate, fear) |
| scare to death(verb, expression, idiom, upset, shock) |
| scramble(noun, informal, device, warning, bell) |
| scream(noun, alert, cry, device, signal) |
| shout(noun, alert, cry, device, signal) |
| sound an alarm(expression, idiom, fear, indication) |
| spinelessness(noun, fear) |
| stagger(verb, shock, agitate, affect, throw) |
| start(shock, fear, surprise, disconcert) |
| sundial(noun, watch, instantaneity, timer, timepiece) |
| tip(noun, sign, alert, device, warning) |
| tip-off(information, sign, notice, alert, caution) |
| touch(verb, trouble, disturb, worry, shock) |
| unhinge(verb, upset, trouble, bother, disturb) |
| unrest(noun, upset, worry, concern, anxiety) |