Firm and not willing to bend, change, or give way; rigid and stubborn.
From the prefix 'un-' (not) plus the verb 'yield' (to give way), plus the suffix '-ing' (making it an adjective). 'Yield' comes from Old English 'geldan' meaning 'to pay or give.' The combination describes something that refuses to give or give up.
The word 'unyielding' describes both physical things (like unyielding stone) and personality traits (like an unyielding person), showing how English often uses the same words for concrete and abstract meanings! Both share the quality of absolute resistance to change.
Complete word intelligence in one call. Free tier — 50 lookups/day.