literally it means wave in Spanish, but used in a lot of Spanish expressions (especially in Mexico) where it refers to a kind of flow, whether of events (like what's been going on) or of a mood. "Que onda", literally "what wave" is the equivalent of "what's up" or "what's going on." "Sacar de onda" or to be "sacado de onda" is to throw off or be thrown off, disconcerted, upset, or to have a mood or flow ruined.
, que onda?"="Hey dude, what's up?"
siempre me saca de onda"="That dumbass always ruins my mood"
Persona 1: "estas enojado conmigo?"
Persona 2: "No, solo medio sacado de onda" =
person 1: "Are you mad at me?"
person 2 "No, just kind of thrown off."