A "crush" on someone that is not associated with a desire for a romantic or sexual relationship. The desire to get to know them and be important to them is purely platonic in nature.
Characterized by admiration, respect and affection for a person.
Usually involves feelings generally associated with having a crush on someone i.e. feeling happy when they talk to you, caring a lot about their opinion of you, looking forward to seeing them, thinking about them a lot, intense happiness when your feelings are reciprocated, etc.
Can either be used as a noun ("I've got a squish on them") or as a verb ("I'm totally squishing on them").
Girl 1: I can't get him out of my head! He's so nice, and smart, and I always feel so special around him!
Girl 2: You know he has a girlfriend, right?
Girl 1: It's not like that! I'm just squishing on him.
To find out that the person you like is gay, as seen in the music video for Carly Rae Jepson's song "Call Me Maybe".
Girl 1: Well, I was gonna ask Tom out, but it turns out he's gay.
Girl 2: Ouch. Carly Rae-Jected.