aroma, breath, broad hint, catchword, clue, condensation trail, contrail, course, cue, cue word, definite odor, detectable odor, effluvium, emanation, essence, evidence, exhalation, flavor, footstep, fragrance, fume, gentle hint, gesture, glimmer, glimmering, hint, hot lead, implication, index, indication, inkling, innuendo, insinuation, intimation, key, key word, kick, lead, line, look, nod, nudge, odor, path, piste, prompt, redolence, savor, scent, sign, signal, signs, smell, stench, step, subtle odor, suggestion, suspicion, symptom, telltale, tip-off, trace, traces, track, tract, trail, vapor trail, vestige, wake, whiff, whisper, wink