'pus-forming' originates from Modern English, composed of the noun 'pus' and the present-participial element 'forming'; 'pus' originates from Latin, specifically the word 'pus', where 'pus' meant 'pus', and 'forming' derives from Latin 'formare', where 'form-' meant 'shape'.

'pus' entered English from Latin 'pus'; 'form' came into English via Old French 'former' and Middle English 'form', with the present participle 'forming' used to create compounds; the compound 'pus-forming' developed in modern medical English to describe suppurative processes.

Initially, the compound meant 'forming pus' and it has retained that specific medical meaning of 'producing pus' in current usage.