To be a fly on the wall Home The Lexicon To be a fly on the wall Thumbnail Phrase or WordTo be a fly on the wallDefinitionTo be observant and unnoticed, often to gain insight or overhear something secretly.LanguageEnglishTypeFaunamorphSubcategoryInsects, Arachnids, Creepy Crawlies…Grammatical SubcategoryNouns: Things/Terms/Labels Previous itemTo be/find a fly in the ointment Next itemTo have no flies on you
