Meaning

noun the tenth month of the Hindu calendar

noun a fluid product of inflammation

noun a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 1

originFrom Middle English pus (15th c.), a borrowing from Latin pus (“pus”). Widely displaced quitter and atter in this sense.

Etymology from Wiktionary, CC BY-SA 3.0