Synonyms of casually

2 Syllables
subtly, thinly, lightly, slowly, faintly
3 Syllables
haltingly, flippantly, leniently, tenuously, timidly, thoughtlessly, heedlessly, slightingly, flimsily, sparsely, airily, breezily, daintily, artlessly, sparingly, obiter
4 Syllables
nonchalantly, ethereally, remotely, frivolously, informally, extraneously, ignorantly, naturally, agilely, haphazardly
5 Syllables
unsubstantially, inadvertently, superficially, unaffectedly, unpretentiously, incidentally
6 Syllables
unintentionally, parenthetically, subordinately
7 Syllables
characteristically