'lamb's-ear' originates from English, a compound of 'lamb' and 'ear', where 'lamb' meant 'young sheep' and 'ear' meant 'ear (body part)'.

'lamb' and 'ear' derive from Old English 'lamb' and 'eare' respectively; the compound term 'lamb's ear' was formed in Early Modern English to describe plant leaves that look like a lamb's ear and later became established as a common name for certain Stachys species.

Initially it referred simply to the ear of a lamb; over time the phrase came to be used figuratively as the common name for plants whose leaves resemble a lamb's ear, while the literal meaning remained.