Filipino word added to the names of women or girls older than you.
Also used in family like "nee-san" in Japanese. For older siblings as a sign of respect.
If some dude you have a crush on calls you Ate it painfully means you're older than him (DUH) and/or he is only interested with being good friends with you. And probably respects your maturity despite the fact that he's older or you're both same aged.