List of offhand synonyms and offhand related words.
Bohemian, abrupt, ad lib, ad libitum, ad-lib, affable, airily, airy, aloof, any old way, any which way, anyhow, at short notice, at sight, blase, brusque, bunglingly, by ear, by the by, by the way, careless, carelessly, casual, casually, cavalier, clumsily, cool, cordial, cursorily, cursory, curt, degage, devil-may-care, disregardant, disregardful, disregardfully, distant, easy, easygoing, en famille, en passant, extemporaneous, extemporaneously, extemporarily, extemporary, extempore, familiar, familiarly, flippant, folksy, forgetful, forgetfully, free and easy, glib, gracious, haphazardly, haymish, heedless, heedlessly, helter-skelter, hit and miss, hit or miss, homely, homey, impromptu, improvisatorial, improvise, improvised, improviso, in passing, inattentively, incidentally, inconsiderate, inconsiderately, indifferent, informal, informally, insouciant, irregular, jury-rigged, lackadaisical, lazy, light-hearted, loose, makeshift, messily, natural, naturally, nonchalant, oblivious, off the cuff, off the hip, off-the-cuff, offhanded, offhandedly, on sight, once over lightly, out of hand, parenthetically, perfunctorily, perfunctory, plain, plainly, promiscuously, reckless, recklessly, regardless, regardlessly, relaxed, relaxedly, respectless, sans ceremonie, simple, simply, slapdash, sloppily, smooth, sociable, spur-of-the-moment, stopgap, superficial, superficially, tactless, tactlessly, thoughtless, thoughtlessly, unaffected, unaffectedly, unassuming, unassumingly, unceremonious, unceremoniously, unconcerned, unconstrained, unconstrainedly, unconventional, undiplomatic, ungracious, unguardedly, unheedful, unheedfully, unheeding, unheedingly, uninterested, unmindful, unmindfully, unofficial, unofficially, unpremeditated, unprepared, unready, unrehearsed, unsolicitous, unsolicitously, unstudied, untactful, unthinking, unthinkingly, unvigilantly, unwarily, without ceremony