'non-uniform-grained' is a modern English compound formed from the negative prefix 'non-' + 'uniform' + the participial adjective-forming element from 'grain' ('grained'), where 'non-' means 'not', 'uniform' means 'of one form or consistent', and 'grain' refers to 'a small hard particle or the texture of a material'.

'uniform' originates from Latin 'uniformis' (uni- 'one' + forma 'form'), and 'grain' comes via Old French 'graine' from Latin 'granum' meaning 'seed' or 'grain'; the modern compound 'non-uniform-grained' arose in technical English (materials science, geology) by combining these elements to describe microstructure or texture.

Individually, 'uniform' originally meant 'of one form' and 'grain' meant 'seed' or 'particle'; combined in modern technical usage the compound has come to mean specifically 'having a nonuniform distribution or size of grains' rather than the original more general senses.