Definition of alone :
1. Hence; Unique; rare; matchless.
2. Of or by itself; by themselves; without any thing more or any one else; without a sharer; only.
3. Quite by one's self; apart from, or exclusive of, others; single; solitary; - applied to a person or thing.
4. Sole; only; exclusive.
5. Solely; simply; exclusively.
only if, unique, only when, altogether, apart, desolate, all, uncomparable, incomparable, companionless, nonpareil, forlorn, merely, unaccompanied, entirely, unexampled, lorn, removed, unequalled, peerless, matchless, isolate, exclusive, lonesome, solo, forsaken, separate, unparalleled, deserted, unsocial, exclusively, completely, whole, single-handed, singly, unrivaled, include, unmatched, simply, just, wholly, totally, but, singular, same, abandoned, unequaled, only, solely, individual
celibate (part of speech: adjective)
intact, abstemious, maiden, spinsterish, solitary, single, asexual, pure, unmarried, ascetic, abstinent, lone, unwed, chaste, virgin, monkish, unplowed, virginal, bachelor, celibate, monastic, old maid
secluded (part of speech: adjective)
ejected, aloof, excommunicated, closeted, confined, secluded, maverick, hermitic, segregated, alienated, xenophobic, antisocial, cloistered, reclusive, blackballed, separated, blacklisted, exiled, ostracized, anonymous, expatriated, banished, lonely, cordoned, sequestered, disbarred, eliminated, deported, outcast, detached, isolated, boycott, extirpated, misanthropic, extradited, excluded
forget (part of speech: verb)