'above-average' is a compound formed from English 'above' and 'average'. 'Above' originates from Old English 'abufan' (be- + up) meaning 'over' or 'higher than'. 'Average' originates from Old French 'avarie' (via Anglo-Norman and later Middle English), a word influenced by Medieval Latin and possibly Arabic roots relating to assessments of damage or customary amounts, which later developed the sense of a typical or mean value.

'average' came into Middle English from Old French 'avarie' (meaning damage or loss in shipping and commerce) and over time its meaning shifted toward the idea of a typical amount or arithmetic mean. The compound phrase 'above average' (two words) has long been used in English; in modern usage it also appears hyphenated as 'above-average' when used attributively before a noun.

Initially, 'average' could refer to customary loss or an assessed amount; over time it evolved into the statistical/typical sense of the 'mean' or 'typical level'. The compound 'above-average' has therefore come to mean 'higher than the mean or typical level'.