skinny-dipping

The term is a modern American English compound, first attested in the mid-20th century. It employs "skinny," an adjective describing extreme thinness where one's skin is prominently visible, as a playful slang synonym for "nude" or "naked." This is combined with "dipping," the verbal noun from "dip," meaning to plunge into water. The compound's logic is transparently euphemistic and humorous, creating a vivid image of the activity it describes by literally referring to "swimming in one's skin." It follows a classic pattern of forming compound nouns to name informal or recreational activities.

Structure: skinny (naked) + dipping (act of immersing) - skinny: Of English origin, from the adjective 'skinny' (very thin, showing the skin). In this compound, it functions as a humorous or euphemistic modifier meaning "naked." - dipping: Of English origin, from the verb 'dip' (to immerse briefly in a liquid) + the suffix '-ing' (which forms the gerund/noun). It denotes the act of immersing oneself.