Word Study
unless
CIDE DICTIONARY
unless, conj. [Formerly, onles, onlesse, onlesse that, that is, in less, in a less case. See On, and Less.].
Upon any less condition than (the fact or thing stated in the sentence or clause which follows); if not; supposing that not; if it be not; were it not that; except; as, we shall fail unless we are industrious. [1913 Webster]
" By the omission of the verb in the dependent clause, unless was frequently used prepositionally, -- a construction common in Shakespeare and still employed colloquially." [1913 Webster]
"Here nothing breeds unless the nightly owl." [1913 Webster]
OXFORD DICTIONARY
unless, conj. if not; except when (shall go unless I hear from you; always walked unless I had a bicycle).
Etymology
ON or IN + LESS, assim. to UN-(1)
THESAURUS
unless
aside from, bar, barring, beside, besides, but, ex, except, except for, except that, excepting, excluding, exclusive of, if not, leaving out, let alone, omitting, outside of, precluding, save, save and except, saving, than, unless that, were it not, withoutROGET THESAURUS
unless
Circumstance
N circumstance, situation, phase, position, posture, attitude, place, point, terms, regime, footing, standing, status, occasion, juncture, conjunctive, contingency, predicament, emergence, emergency, exigency, crisis, pinch, pass, push, occurrence, turning point, bearings, how the land lies, surroundings, context, environment, location, contingency, dependence (uncertainty), causation, attribution, circumstantial, given, conditional, provisional, critical, modal, contingent, incidental, adventitious, limitative, in the circumstances, under the circumstances, the circumstances, conditions, thus, in such wise, accordingly, that being the case, such being the case, in view of the circumstances, that being so, sith, since, seeing that, as matters stand, as things go, as times go, conditionally, provided, if, in case, if so, if so be, if it be so, depending on circumstances, in certain circumstances, under certain conditions, if it so happen, if it so turn out, in the event of, in such a contingency, in such a case, in such an event, provisionally, unless, without, according to circumstances, according to the occasion, as it may happen, as it may turn out, as it may be, as the case may be, as the wind blows, pro re nata, yet are my sins not those of circumstance.Unconformity
N unconformity, nonconformity, unconformity, disconformity, unconventionality, informality, abnormity, abnormality, anomaly, anomalousness, exception, peculiarity, infraction of law, breach, of law, violation of law, violation of custom, violation of usage, infringement of law, infringement of custom, infringement of usage, teratism, eccentricity, bizarrerie, oddity, je ne sais quoi, monster, monstrosity, rarity, freak, freak of Nature, weirdo, mutant, rouser, snorter, individuality, idiosyncrasy, originality, mannerism, aberration, irregularity, variety, singularity, exemption, salvo, nonconformist, nondescript, character, original, nonesuch, nonsuch, monster, prodigy, wonder, miracle, curiosity, flying fish, black sheep, black swan, lusus naturae, rara avis, queer fish, mongrel, random breed, half-caste, half-blood, half-breed, metis, crossbreed, hybrid, mule, hinny, mulatto, tertium quid, hermaphrodite, phoenix, chimera, hydra, sphinx, minotaur, griffin, griffon, centaur, saggittary, kraken, cockatrice, wyvern, roc, dragon, sea serpent, mermaid, merman, merfolk, unicorn, Cyclops, men whose heads do grow beneath their shoulders, teratology, fish out of water, neither one thing nor another, neither fish nor fowl, neither fish flesh nor fowl nor good red herring, one in a million, one in a way, one in a thousand, outcast, outlaw, off the beaten track, oasis, uncomformable, exceptional, abnormal, abnormous, anomalous, anomalistic, out of order, out of place, out of keeping, out of tune, out of one's element, irregular, arbitrary, teratogenic, lawless, informal, aberrant, stray, wandering, wanton, peculiar, exclusive, unnatural, eccentric, egregious, out of the beaten track, off the beaten track, out of the common, out of the common run, beyond the pale of, out of the pale of, misplaced, funny, unusual, unaccustomed, uncustomary, unwonted, uncommon, rare, curious, odd, extraordinary, out of the ordinary, strange, monstrous, wonderful, unexpected, unaccountable, outre, out of the way, remarkable, noteworthy, queer, quaint, nondescript, none such, sui generis, unfashionable, fantastic, grotesque, bizarre, outlandish, exotic, tombe des nues, preternatural, denaturalized, heterogeneous, heteroclite, amorphous, mongrel, amphibious, epicene, half blood, hybrid, androgynous, androgynal, asymmetric, adelomorphous, bisexual, hermaphrodite, monoclinous, qualified, singular, unique, one-of-a-kind, newfangled, novel, non-classical, original, unconventional, unheard of, unfamiliar, undescribed, unprecedented, unparalleled, unexampled, unconformably, except, unless, save barring, beside, without, save and except, let alone, however, yet, but, once in a blue moon, once in a million years, Int, what on earth!, what in the world!, What the devil!, Holy cow!, Can you top that?, Sacre bleu, never was seen the like, never was heard the like, never was known the like, I could hardly believe it, I saw it, but I didn't believe it.Qualification
N qualification, limitation, modification, coloring, allowance, grains of allowance, consideration, extenuating circumstances, mitigation, condition, proviso, prerequisite, contingency, stipulation, provision, specification, sine qua non, catch, string, strings attached, exemption, exception, escape clause, salvo, saving clause, discount, restriction, fine print, qualifying, qualified, conditioned, restricted, hedged, conditional, exceptional, hypothetical, contingent, provided, provided that, provided always, if, unless, but, yet, according as, conditionally, admitting, supposing, on the supposition of, with the understanding, even, although, though, for all that, after all, at all events, approximately, in a limited degree (smallness), somewhat, sort of, something like that, to a certain extent, to a degree, in a sense, so to speak, with grains of allowance, cum grano salis, with a grain of salt, exceptis excipiendis, wind and weather permitting, if possible, subject to, conditioned upon, with this proviso, if the good lord is willing and the creeks don't r, catch-, Degrees of Evidence.For further exploring for "unless" in Webster Dictionary Online