hour-and-a-half

The phrase "hour-and-a-half" is a modern English compound noun formed through the straightforward combination of common, ancient words to denote a specific duration. "Hour" originates from the Greek 'hōra', meaning a limited time or season, entering English via Latin 'hora' and Old French 'hore'. "Half" derives from the Old English 'healf', meaning a side or part, from Proto-Germanic halbaz. The structure "X and a Y" is a classic English pattern for expressing a quantity, as seen in phrases like "cup and a half" or "mile and a quarter." The logic of the phrase is purely arithmetic and descriptive, literally signaling the sum of one hour plus one half of an hour, which has become a standard lexical unit for the ninety-minute period.

This is a fixed compound phrase. It is not productively formed from separable morphemes in the modern sense but is a lexicalized combination of three English words: 'hour', the conjunction 'and', the indefinite article 'a', and the noun 'half'.