The word "telly" is a British colloquialism that emerged in the mid-20th century as a clipped form of "television". "Television" itself is a compound from Greek "tele-" (far off, at a distance) and Latin "visio" (seeing). The informal clipping to "telly" follows a common pattern in English for creating familiar, shorter names for new technologies, similar to "fridge" from "refrigerator". Its usage reflects the rapid domestication and integration of the broadcast medium into everyday life and casual speech.

The word is a clipped form (shortening) of the word "television". It does not contain separable, meaningful morphemes in its current form.