'nonflowering' originates from the prefix 'non-' (from Latin 'non' meaning 'not') combined with 'flowering', formed from 'flower' + the gerund/participial suffix '-ing'.

'flower' developed from Old French 'flor'/'fleur', which came from Latin 'flos, floris'; the suffix '-ing' is a Germanic/Old English verbal noun/forming element; the prefix 'non-' has been used in English since Late Middle/Modern English to negate adjectives and nouns, and 'nonflowering' is a relatively modern compound formed in English by adding 'non-' to 'flowering'.

Initially the elements meant 'not' + 'producing flowers'; over time the compound retained this literal meaning and remains used to denote plants that do not produce flowers.