accidental

adjective

1 accidental damage | an accidental meeting:

fortuitous, chance, occurring by chance/accident, adventitious, fluky, coincidental, casual, serendipitous, random, aleatory;

unexpected, unforeseen, unanticipated, unlooked-for;

unintentional, unintended, inadvertent, involuntary, unplanned, unpremeditated, unthinking, unmeant;

unwitting, unknowing, unconscious, subconscious;

mistaken, misguided.

▷antonyms intentional, planned.

2 the location is accidental and contributes nothing to the poem:

incidental, unimportant, by the way, by the by, supplementary, subsidiary, subordinate, secondary, marginal, minor, lesser, accessory, peripheral, tangential, extraneous, extrinsic, parenthetical, irrelevant, immaterial, beside the point, of little account, unnecessary, non-essential, inessential.

▷antonyms essential, central.

accidental Oxford Dictionary of English