'floral-obsessed' originates as a modern English compound combining 'floral' and 'obsessed', where 'floral' derives from Latin 'flos, floris' meaning 'flower' (via Late Latin 'floralis'), and 'obsessed' ultimately comes from Latin 'obsidere'/'obsessus' meaning 'to besiege' or 'to be occupied by'.

'floral' entered English from Late Latin 'floralis' (via Old French/Medieval Latin influences) meaning 'of flowers', while 'obsess' developed from Latin 'obsidere' → past participle 'obsessus' and came into English with the sense of being mentally 'beset' or preoccupied; the modern compound 'floral-obsessed' is a recent, colloquial formation combining these elements.

Individually, 'floral' originally meant 'of or relating to flowers', and 'obsessed' originally had physical/strategic senses like 'besieged' before shifting toward psychological preoccupation; together the compound has come to mean 'excessively or preoccupationally fond of flowers' in current usage.