five-and-a-half
UK[ˌfaɪv‿ən‿ə ˈhɑːf]US[ˌfaɪv‿ən‿ə ˈhæf]
adj
Being equal to or lasting five and a half units (e.g., years, hours, miles)
n
The number or quantity that is five and a half
Etymology
The phrase "five-and-a-half" is a modern English numerical compound, following a pattern established in Middle English for expressing mixed numbers. Its logic is purely arithmetic and syntactic, combining the Old English cardinal "fīf" (from Proto-Germanic fimf), the conjunction "and" (from Old English "and"), the indefinite article "a" (a weakened form of Old English "ān", meaning "one"), and "half" (from Old English "healf", meaning "side" or "part"). Unlike classical compounds with fused Greco-Latin roots, this phrase remains transparently analytical, its meaning directly derived from the sum of its constituent words. It represents a straightforward, compositional method in English for denoting a quantity midway between two whole numbers.
Analysis
This is a fixed compound phrase formed from the cardinal number "five", the conjunction "and", the indefinite article "a", and the noun "half". Each element retains its standard English meaning and grammatical function within the idiomatic structure.
Examples
The film is suitable for children aged five-and-a-half and above.
He ran the five-and-a-half-mile race in under an hour.
We need five-and-a-half cups of flour for this recipe.