'stepwise-grown' is a modern English compound formed from 'stepwise' + 'grown'. 'stepwise' itself is built from 'step' + the suffix '-wise' meaning 'in the manner of', and 'grown' is the past participle of 'grow'.

'stepwise' developed in Modern English by combining 'step' (from Old English 'stēpp' / 'stǣp') and the Old English/Old Norse suffix '-wise' ('-wīs'), meaning 'in the manner of'. 'grown' derives from Old English 'grōwan' (infinitive) with past participle forms that evolved into Modern English 'grown'. The compound 'stepwise-grown' is a relatively recent descriptive formation in technical and scientific usage.

The elements originally referred separately to 'a step' and to the act/state of being 'grown'; combined, the compound came to mean specifically 'having grown by discrete steps' rather than simply 'having grown'.