un ‧ in ‧ ten ‧ tion ‧ al /ˌʌnɪnˈtenʃ ə nəl◂/ BrE AmE adjective
[ Word Family: adjective : intended ≠ UNINTENDED , ↑ intentional ≠ ↑ unintentional , ↑ intent ; noun : ↑ intent , ↑ intention ; verb : ↑ intend ; adverb : ↑ intentionally ≠ ↑ unintentionally ]
not done deliberately OPP deliberate :
I know she upset you, but I’m sure it was unintentional.
—unintentionally adverb