Purge is from Old French purgier, from Latin purgare ('to cleanse, purify'), from purus ('pure') + agere ('to do, drive'). Important recorded forms include purgare (Latin), purus (Latin), and agere (Latin). Morphologically, the word preserves a built structure whose named elements carry the historical sense into English. The modern sense remains close to that composition, with the parts narrowing into a single lexical item. In current use it covers to rid of unwanted elements; a sudden removal of people or things. The wider family includes derived forms such as purger, purgation, purgative, and purging and related words such as purgatory, expurgate, pure, and purify.