English Dictionary

yandere

/ˈjɑːndɛɹeɪ/

noun

(chiefly Japanese fiction) A character, usually a girl, who has an obsessive and possessive side in regards to their crush, ready to use violent and murderous means to maintain an exclusive bond.

She is a yandere who will do anything to protect her love interest.

意味（1）

(chiefly Japanese fiction) A character, usually a girl, who has an obsessive and possessive side in regards to their crush, ready to use violent and murderous means to maintain an exclusive bond.

And it finally answered the question as to whether Senjougahara is tsundere or yandere.