'single-flowered' is a compound formed from 'single' + 'flowered'. 'single' originates from Latin, specifically the word 'singulus', where 'sing-' meant 'one, single'. 'flower' originates from Old French 'flor'/'flour', ultimately from Latin 'flos, floris', meaning 'flower'. The adjectival suffix '-ed' is added to form 'flowered' meaning 'having flowers'.

'single' entered English via Old French 'sengle' and Middle English 'single' from Latin 'singulus'. 'flower' came into English from Old French 'flor'/'flour', from Latin 'flos, floris'; adding the English suffix '-ed' produced the adjective 'flowered'. The compound 'single-flowered' is a modern descriptive formation combining these elements.

Initially, the roots meant 'one' (from 'singulus') and 'flower' (from 'flos'). Over time they have remained close to their original senses; combined as 'single-flowered' the phrase now specifically denotes 'having a single flower' (often used in botanical descriptions).