From Old French Lucie, the vernacular form of Lucia. It is sometimes assumed that Lucy is a pet form of Lucinda, but there is no etymological justification for this assumption. It was in fairly widespread use in the Middle Ages, and increased greatly in popularity in the 18th century and again in the 1990s. In Ireland it serves as an Anglicized form of Irish Luíseach.
English: habitational name, probably from either of two places called Lydford, in Devon and Somerset. The first is named with the river name Lyd (from Old English hlȳde ‘noisy stream’) + Old English ford, i.e. ‘ford over the Lyd river’.Lydford in Somerset was named ‘ford over the noisy stream’, from Old English hlȳde + ford.