The abbreviation q.v. is short for the Latin quod vide, meaning "which see".
It is useful when making cross-references, directing the reader to another part of the text, book or article.
e.g. q.v. "Latin: cf.".
Abbreviated: a.m. & p.m., cf., e.g., et al., etc., i.e., N.B., P.S., Q.E.D., q.v., viz.
Non abbreviated: ad hoc, de facto, modus operandi, non sequitur, pro rata, quid pro quo, sic, vice versa.