THESAURUS
occasional
accessory, accidental, accompanying, additional, ado, adventitious, afloat, afoot, aleatory, auxiliary, behind the scenes, by-the-way, casual, causal, causative, ceremonial, circumstantial, conditional, constitutive, contingent, current, decisive, determinative, doing, effectual, etiological, eventuating, extra, few, formative, going on, happening, in hand, in the wind, incidental, inessential, infrequent, institutive, intermittent, irregular, nonessential, occurring, odd, off, on, on foot, ongoing, originative, out-of-the-way, parenthetical, part-time, particular, passing, periodic, pivotal, prevailing, prevalent, provisional, random, rare, resultant, ritual, scarce, seldom, side, spare, special, sporadic, supplementary, taking place, uncommon, under way, unessential, unfrequent
ROGET THESAURUS
occasional
Discontinuity
N
discontinuity, disjunction, anacoluthon, interruption, break, fracture, flaw, fault, crack, cut, gap, solution of continuity, caesura, broken thread, parenthesis, episode, rhapsody, patchwork, intermission, alternation, dropping fire, discontinuous, unsuccessive, broken, interrupted, dicousu, disconnected, unconnected, discrete, disjunctive, fitful, spasmodic, desultory, intermitting,
occasional, intermittent, alternate, recurrent, at intervals, by snatches, by jerks, by skips, by catches, by fits and starts, skippingly, per saltum, longo intervallo, like 'angel visits few and far between'.
Uncertainty
N
uncertainty, incertitude, doubt, doubtfulness, dubiety, dubitation, dubitancy, dubitousness, hesitation, suspense, perplexity, embarrassment, dilemma, bewilderment, timidity, vacillation, diaporesis, indetermination, vagueness, haze, fog, obscurity, ambiguity, contingency, dependence, dependency, double contingency, possibility upon a possibility, open question, onus probandi, blind bargain, pig in a poke, leap in the dark, something or other, needle in a haystack, needle in a bottle of hay, roving commission, precariousness, fallibility, uncertain, casual, random, changeable, doubtful, dubious, indecisive, unsettled, undecided, undetermined, in suspense, open to discussion, controvertible, in question, vague, indeterminate, indefinite, ambiguous, equivocal, undefined, undefinable, confused, mystic, oracular, dazed, perplexing, enigmatic, paradoxical, apocryphal, problematical, hypothetical, experimental, unpredictable, unforeseeable (unknowable), fallible, questionable, precarious, slippery, ticklish, debatable, disputable, unreliable, untrustworthy, contingent, contingent on, dependent on, subject to, dependent on circumstances,
occasional, provisional, unauthentic, unauthenticated, unauthoritative, unascertained, unconfirmed, undemonstrated, untold, uncounted, in a state of uncertainty, in a cloud, in a maze, bushed, off the track, ignorant, afraid to say, out of one's reckoning, astray, adrift, at sea, at fault, at a loss, at one's wit's end, at a nonplus, puzzled, lost, abroad, d_esorient_e, distracted, distraught, pendente lite, sub spe rati, Heaven knows, who can tell? who shall decide when doctors disagr.