The term "pin-brained" is often used to describe someone who is perceived as narrow-minded or lacking intelligence. There are many synonyms for this derogatory term, including: foolish, dim-witted, dense, stupid, thick, witless, and brainless. Each of these words suggests a lack of mental acuity, and they can be used interchangeably to convey a similar meaning. Other synonyms for "pin-brained" might include words like thoughtless, clueless, or unobservant. All of these words suggest a certain lack of awareness or understanding, and they can be used to describe someone who is seen as lacking in either intellectual or emotional intelligence.