'lamb' originates from Old English, specifically the word 'lamb', ultimately from Proto-Germanic '*lambaz', where the root '*lamb-' meant 'young sheep'.

'lamb' changed from Old English 'lamb' (and from Proto-Germanic '*lambaz') and eventually became the modern English word 'lamb' with little change in form.

Initially, it meant 'young sheep', and over time it has largely retained this meaning, though it is also used metaphorically in some expressions.