[1] : The Collaborative International Dictionary of English v.0.48

accidentally \ac`ciden"tally\, adv.
   in an accidental manner; unexpectedly; by chance;
   unintentionally; casually; fortuitously; not essentially.
   1913 webster

[2] : WordNet (r) 2.0

accidentally
     adv 1: without advance planning; "they met accidentally" syn: by
            chance, circumstantially, unexpectedly ant: intentionally
     2: in an incidental manner; "these magnificent achievements
        were only incidentally influenced by oriental models"
        syn: incidentally, by chance
     3: without intention; in an unintentional manner; "she hit him
        unintentionally" syn: unintentionally ant: intentionally,
         intentionally
see also:
by chance circumstantially unexpectedly intentionally incidentally by chance 
unintentionally 

Accidentally >> A Words
Accidentally, definition of term: Accidentally
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