'flower-hater' originates from Modern English by combining the noun 'flower' and the agent noun 'hater' (formed from the verb 'hate' + suffix '-er', meaning 'one who').

'flower' comes into English via Middle English 'flour'/'flower' from Old French 'flor', ultimately from Latin 'flos, floris' meaning 'blossom'; 'hate' is from Old English 'hǣtan'/'hatan' (via Proto-Germanic), and the agent suffix '-er' developed in Old/Middle English to form nouns meaning 'one who'. The compound 'flower-hater' is a modern, transparent formation in English.

The components originally denoted 'blossom' and 'strong dislike' separately; when combined in Modern English they form the straightforward meaning 'a person who hates flowers', with occasional figurative extension to those who dislike 'flowery' styles.