Learn the meaning of Posh with clear definitions and helpful usage examples. The word " posh " is an intriguing term with a rich history and a range of meanings . Here’s an in-depth analysis of the word covering its etymology, meanings , connotations, usage, and cultural implications. posh (third-person singular simple present poshes, present participle poshing, simple past and past participle poshed) (normally in the phrasal verb posh up) To make posh or posher (more posh ). synonym Synonym: poshen The meaning of POSH is elegant, fashionable. How to use posh in a sentence.