a clothing item commonly used by trans masc people to compress their chest, giving a more masculine look
"yesterday I went shopping online for a binder"
a type of teacher that should not be teaching her subject, usually a teacher that no one likes
my teacher is a binder, she teaches Spanish and is apparently everything but Spanish.
School binders are a product of hell, they are used as holders for your hellish school assignments.
"Oh hi Billy what are we doing today in class" "Oh hi Ian we are throwing our school binders out the window to start a fire!"