1.
suffix forming nouns denoting a person or thing performing the action of a verb, or an agent more generally (actor; escalator; tailor) (see also -ATOR, -ITOR).
Etymology: L -or, -ator, etc., sometimes via AF -eour, OF -{euml}or, -{euml}ur 2.
suffix forming nouns denoting state or condition (error; horror).
Etymology: L -or -oris, sometimes via (or after) OF -or, -ur 3.
suffix forming adjectives with comparative sense (major; senior).
Etymology: AF -our f. L -or 4.
suffix US -OUR(1).