| faltering |
| feckless(adjective, indifferent, unsympathetic, inattentive, uninterested) |
| fed up(expression, adjective, cool, indifferent, sophisticated) |
| fervorless |
| fine(adjective, calm, weak, smooth, soft) |
| flat(adjective, weak, smooth, gentle, cold) |
| forgetful(adjective, indifferent, unsympathetic, inattentive, uninterested) |
| frigorific |
| glutted(adjective, cool, indifferent, sophisticated, apathetic) |
| half hearted(expression, idiom) |
| hard(adjective, mean, cool, unpleasant, cold) |
| hard-hearted(adjective, calm, indifferent, restrained, unsympathetic) |
| hardened(adjective, indifferent, unsympathetic, inattentive, uninterested) |
| harsh(adjective, mean, hard, cool, unpleasant) |
| heartless(adjective, mean, hard, cool, unpleasant) |
| heavy(adjective, lethargic, languid, indolent) |
| heedless(adjective, dull, indifferent, unsympathetic, sluggish) |
| ho-hum(adjective, calm, weak, smooth, soft) |
| impartial(adjective, indifferent) |
| impassible(adjective, temper, cold, negative, behave) |