| serene(adjective, calm, quiet, gentle, restrained) |
| serious(adjective, reasonable, keen, deep, rational) |
| sharp(adjective, knowledgeable, cultured, educated, erudite) |
| skilled(adjective, sound, knowledgeable, cultured, educated) |
| sober(adjective, calm, cool, sound, reasonable) |
| solemn(adjective, sound, knowledgeable, cultured, educated) |
| solid(adjective, sound, knowledgeable, cultured, educated) |
| sound(adjective, reasonable, sensible, knowledgeable, intellectual) |
| stable(adjective, sound, reasonable, sensible, intellectual) |
| stayed(verb, excitability) |
| studied(adjective, sound, knowledgeable, cultured, educated) |
| studious(adjective, reasonable, keen, deep, sober) |
| subconscious(adjective, reasoning, intellectual, mental) |
| submissive(adjective, calm, quiet, gentle, restrained) |
| synthetic(adjective, sound, reasonable, sensible, intellectual) |
| theoretical(adjective, moral, abstract, metaphysical, philosophical) |
| thinking(adjective, sound, reasonable, keen, sensible) |
| together(adjective, sound, reasonable, sensible, intellectual) |
| tolerant(adjective, calm, quiet, gentle, restrained) |
| tranquil(adjective, calm, quiet, gentle, restrained) |