1. stupid or foolish; lacking intelligence or common sense
Usage: informal; derogatory

Examples

• That was a knotheaded decision to make without thinking it through.
• He made a knotheaded mistake by forgetting his keys again.
• Only a knotheaded person would try to fix the computer without reading the manual.
• She called him knotheaded for believing that obvious lie.
• His knotheaded behavior got him into trouble at work.