'healthy-looking' originates from English, formed by combining the adjective 'healthy' and the present participle 'looking'. The element 'healthy' derives ultimately from Old English 'hǣlþ' (or 'hælþ'), where 'hǣl' meant 'wholeness, health', and 'looking' comes from Old English 'lōcian', meaning 'to look'.

'healthy' developed from Old English 'hǣlþ' → Middle English 'helthe/healthy' and became the modern adjective 'healthy'. 'look' (from Old English 'lōcian') passed through Middle English forms (e.g. 'loken') to become modern 'look'; the compound 'healthy-looking' is a relatively recent Modern English formation combining these elements.

Individually, 'healthy' originally referred to 'wholeness' or 'soundness' and 'look' to the act of seeing; combined as 'healthy-looking' the phrase came to mean 'appearing to be healthy' (an outward appearance rather than a statement of actual health).