Postule

Postule is a noun that is chiefly encountered as an archaic or historical English spelling of pustule, a small, inflamed lesion on the skin or mucous membranes that contains pus. In contemporary medical usage, pustule is the standard term, and postule appears mainly in older texts or etymological discussions rather than in current clinical writing.

The form Postule derives from Latin pustula, passing through Old French pustule into English. In early modern medical literature, postule occasionally appeared as a variant spelling or transcription of pustule, reflecting the orthographic conventions of the period. Because it is regarded as obsolete, most modern dictionaries label postule as archaic or historical.

Today, postule has little to no standing outside scholarly references or discussions of the history of dermatological terminology. Readers encountering the term should interpret it as an historical variant meaning pustule, rather than a distinct clinical concept. The term is easy to confuse with related words such as pustule, which describes the lesion, and postulate, a completely different concept in logic or science.