(idiomatic) Having enough familiarity with another person to call them by their first name, as opposed to their surname.

Alternative spelling of first-sale doctrine

(grammar) The dual of the first-person form of a verb or pronoun, which in some languages can either be inclusive ("you and I") or exclusive ("he and I"). In other languages, there is no distinction.

Not the first time one has been in a particular situation; used to indicate past experience.

(historical) The period of Egyptian history from the end of the Old Kingdom to the start of the Middle Kingdom (comprising the Seventh/Eighth, Ninth, Tenth, and early Eleventh dynasties), characterized by a loss of central authority in favor of local nomarchs.

(chiefly in the negative) To have any knowledge (about something); have a clue. / Used other than figuratively or idiomatically: see have, first, idea.

To not know anything about something.

To initiate something.

A position in Rugby football in the back line.

plural of first five-eighth