| quick(adjective, understanding, cool, keen, sharp) |
| quick-witted(adjective, cool, sharp, smart, sensible) |
| sane(adjective, reasonable, sensible, rational, stable) |
| scholarly(adjective, knowledge, experience, skill, expert) |
| sensile(adjective, open, sensible, sympathetic, active) |
| sensitive to(expression, adjective, understanding, keen, sensible) |
| sensory(adjective, responsive, perceptive, susceptible, receptive) |
| sharp-eyed |
| sharp-witted(wise, insightful, sagacious) |
| skilled(adjective, knowledge, experience, delicate, skill) |
| sober(adjective, reasonable, realistic, sane, level-headed) |
| sophisticated(adjective, cool, reasonable, significant, familiar) |
| sound(adjective, reasonable, sharp, sensible, rational) |
| sure(adjective, understanding, keen, sensible, certain) |
| susceptible(adjective, open, sensible, sympathetic, active) |
| susceptive(adjective, open, sensible, sympathetic, active) |
| undeceived |
| up(adjective, familiar, knowledgeable, skilled, informed) |
| wakeful(keen, alert, careful, attentive, conscious) |
| waking(conscious, wide-awake, wakeful) |