| idyllic(adjective, peaceful) |
| indifferent(adjective, calm, dull, quiet, cool) |
| indolent(adjective, mild, relaxed, tolerant, laid-back) |
| inexcitable(adjective, cool, blank, aloof, unemotional) |
| inscrutable(adjective, quiet, cool, moderate, gentle) |
| jejune(adjective, calm, dull, quiet, kind) |
| laid-back(adjective, calm, quiet, cool, moderate) |
| languid(adjective, dull, quiet, flat, slow) |
| leisurely |
| light(adjective, calm, quiet, cool, weak) |
| low-key(adjective, quiet, cool, smooth, mild) |
| modest(adjective, quiet, gentle, aloof, reserved) |
| noiseless(adjective, calm, quiet, smooth, tranquil) |
| non-aggressive(adjective, peaceful) |
| nonbelligerent(calm, quiet, friendly, easygoing, compliant) |
| peacemaking(soothing, conciliatory, appeasing) |
| poker-faced(adjective, cool, blank, aloof, unemotional) |
| regular(adjective, calm, dull, quiet, smooth) |
| reposing(adjective, quiet, cool, smooth, mild) |
| repressed(adjective, calm, relaxed, tranquil, easygoing) |