偶一

accidentally / once in a while / very occasionally

accidental / image / pair / mate

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

to do sth once in a while (idiom) / to do sth more as an exception than the rule