ETYM Old Eng. ladi, laefdi, as. hlaefdige, hlaefdie; as. hlâf loaf + a root of uncertain origin, possibly akin to Eng. dairy. Related to Loaf, Lord.
1. A polite name for any woman.
2. A woman of aristocratic family; SYN. noblewoman, peeress.

British title, In the UK, the formal title of the daughter of an earl, marquis, or duke; and of any woman whose husband is above the rank of baronet or knight, as well as (by courtesy only) the wives of these latter ranks.