dillweed

Popularized by the Beavis and Butt-head TV series, "dillweed" is a derogatory term used to describe irrational/dumb behavior and low intellectual capacity, usually resulting in some sort of consequence. Literally, "dillweed" likens someone to pubic hair - "dill" being slang for "penis" (think dill pickle) and "weed" being slang for "hair."