na-adjective, noun which may take the genitive case particle 'no'
forgetful; prone to forgetting; negligent
Describes a tendency to forget things or be inattentive. Often used with ~になる or as a な-adjective modifying a person or behavior.
Lately I've become forgetful.
He has a forgetful nature.
Ateji spelling using 勝ち; rarely used in modern writing.
Compound of 忘れ (continuative form of 忘れる 'to forget') + がち (suffix meaning 'apt to do' or 'tend to').