The process of aging or growing old, or archaic term for an old horse or aged animal.
From Old English 'eld' (age) with the gerund suffix '-ing.' In some dialects, 'elding' specifically refers to an aged or worn-out horse, similar to how 'colt' means young and 'steed' can mean noble.
Before modern veterinary science, people had specific words for every age and condition of animals—'elding' for an old horse tells you that medieval farmers thought deeply about the lifecycle of their working animals.
Complete word intelligence in one call. Free tier — 50 lookups/day.