the word 'unmask' is a transparent english formation, combining the native germanic prefix 'un-' with the borrowed noun 'mask'. the prefix 'un-', with its core sense of reversal, is added to the action implied by the noun 'mask', which traces back to medieval latin 'masca' meaning "specter, nightmare" and later "mask". this literal combination to mean "remove a mask" is first attested in the late 16th century. its figurative sense, "to expose the true character of something concealed," developed rapidly by the early 17th century, demonstrating a logical semantic extension from the physical act of revelation to the abstract. the word's construction perfectly illustrates the english capacity to create new verbs by pairing a productive native prefix with a romanic root to express a clear and direct concept.

Structure: un (reverse action) + mask (covering) - un: a prefix of Germanic origin (old english un-, on-), meaning "not" or "reversal of an action". - mask: a noun of latin origin (via italian maschera and medieval latin masca), meaning "a covering for the face".