Peruse

The verb 'to peruse' should be used to mean 'read thoroughly. This is what pedants expect, and should be the sense used in academic writing. It isn't always used in this way, however: in informal English, it is perhaps more commonly used to mean 'to read quickly', 'to scan [a text]', 'to riffle through pages, indexes and so on to find a reference'. This meaning, which is often rebuked in style guides and should therefore be avoided, seems to be a twentieth century development, originally jocular in intention; but the sense of 'to read', either with or without great care, has existed since Early Modern English. Dr Johnson himself said, in the Idler of 13th Jan. 1759, "Whatever is common is despised. Advertisements are now so numerous that they are very negligently perused" (17/2, cited OED).

• The noun is perusal.

Etymological note: peruse is formed from the Latin prefix per- 'thoroughly' and utor - uti - usus 'to use', 'to take benefit from', 'to exercise [a skill]', as applied to written texts. Peruse was first used in English with the sense of 'examine [a witness in a law court]'.