noun
A loanword from English, used for a keepsake or memento, especially from travel. Less common than お土産 (おみやげ) in everyday Japanese, but understood.
旅行のスーベニアにキーホルダーを買った。
I bought a keychain as a souvenir from the trip.
Loanword from English 'souvenir', itself from French 'souvenir' meaning 'to remember'.