Whacking Day

Used as an insult meaning someone is thoughtless or foolish. The literal image of a hollow head drives the meaning, but as a fixed expression it functions as a set insult rather than a transparent description.

Refers to the act of a crowd booing or jeering a performer or public figure. The verb form is abuchear. Common in sports and political contexts.

A colorful threat meaning someone will face harsh punishment or retaliation. Not literal. Trasero is a mild, colloquial word for buttocks.

Literally a shoe shiner. Used both literally and as a derogatory term implying a servile, low-status occupation. The connotation depends heavily on context and tone.