The word "tidbit" originated in the 17th century as an alteration of the earlier English dialect word "titbit." The first element, "tit," is a dialectal word meaning "small" or "pet," and the second element, "bit," straightforwardly means "a small piece." The change from "titbit" to "tidbit" is thought to be influenced by the archaic word "tid," meaning "fond" or "tender," which itself derives from Old English tiddre ("weak, frail"). Thus, the word's journey reflects a folk etymology that softened the original form, embedding a sense of something small, delicate, and pleasing, which perfectly aligns with its modern meanings of a dainty morsel or a choice scrap of news.

The word "tidbit" is a simplex word in modern English, formed from a dialectal alteration of an earlier compound. Its components are not productively separable morphemes in contemporary usage.