Latin Quirītis most likely stems from an earlier *quiri-. The origin of the latter is uncertain. Since the quirīs is connected with Sabellic immigrants into Rome in ancient legends, it may be a loanword. Ancient etymologies derived the term from the Sabine word for "spear", or from the Sabine capitol of Cures, after the Sabine people were assimilated early in Roman history.
The etymology *ko-wir-, then *co-uiri-um, 'assembly of the men', has been proposed by some scholars, although De Vaan (2008) notes that it "is not credible phonetically and not very compelling semantically".
Combined in the phrase populus Romanus quirites (or quiritium) it denoted the individual citizen as contrasted with the community. Hence ius quiritium in Roman law is full Roman citizenship. Subsequently the term was applied (sometimes in a deprecatory sense, cf. Tac. Ann. ~. 42) to the Romans in domestic affairs, Romani being reserved for foreign affairs.