2. RELATIVE TIME; Time with reference to an effect or purpose
[Antonyms: (timeliness) occasion.]
[Nouns] untimeliness, intempestivity, unseasonableness, inexpedience; unsuitable time, improper time; unreasonableness; evil hour; contretemps; intrusion; anachronism [more].
bad time, wrong time, inappropriate time, not the right occasion, unsuitable time, inopportune time, poor timing.
lose an opportunity, throw away an opportunity, waste an opportunity, neglect an opportunity [more]; allow the opportunity to pass, suffer the opportunity to pass, allow the opportunity to slip, suffer the opportunity to slip, allow the opportunity to go by, suffer the opportunity to go by, allow the opportunity to escape, suffer the opportunity to escape, allow the opportunity to lapse, suffer the opportunity to lapse, allow the occasion to pass, allow the occasion to slip by; waste time (be inactive) [more]; let slip through the fingers, lock the barn door after the horse is stolen.
[Adjectives] ill-timed, mistimed; ill-fated, ill-omened, ill-starred; untimely, unseasonable; out of date, out of season, out of tune; inopportune, timeless, intrusive, untoward, mal a propos, unlucky, inauspicious, infelicitous, unbefitting, unpropitious, unfortunate, unfavorable; unsuited [more]; inexpedient [more].