It sounds like you're asking about a specific route or concept in football (American) — possibly a play or coverage adjustment.
isn’t a standard universal term, but in some defensive systems (especially in the NFL or college), "Joker" refers to a hybrid player (LB/DE or S/LB) who moves around pre-snap. "Deep post" is a passing route where the receiver runs straight downfield, then angles toward the goal post at about 45 degrees. ny joker
