うっかり
うっかり · ukkari · JLPT N3 · adverb
carelessly
ukkari sounds like oops, carry: you carried it off without thinking
うっかり is a Japanese mimetic word for a lapse of attention. It is close to うかうか, meaning absent-mindedly. You will often hear it in うっかりする (to slip up) and うっかりミス (a careless mistake).