From Welsh 'Eluned' meaning 'idol, image' or Old French 'linette' (linnet bird).
Lynette's identity is inseparable from the world of Arthurian legend, where she enters the story as one of its more spirited characters. She appears in the medieval Welsh tradition under the name Luned or Eluned — derived from a Welsh root possibly meaning 'idol' or 'image' — as a magical maiden associated with the Lady of the Fountain. Alfred Lord Tennyson transmuted her into Lynette in his 1872 poem 'Gareth and Lynette' (part of the Idylls of the King), giving her a memorable arc from haughty aristocrat who disdains the disguised prince Gareth to admiring companion who witnesses his valor.
Tennyson's Lynette is sharp-tongued and proud, and her eventual softening made the name feel romantic without being passive. The name moved into English-speaking use largely through Tennyson's influence in the Victorian and Edwardian periods, when Arthurian culture enjoyed a major revival in literature, painting, and interior design. It was the Pre-Raphaelite moment for baby names, and Lynette, Elaine, and Guinevere all saw upticks in birth registers.
The spelling Linette and Lynnette also developed, following the general Victorian tendency to ornament names with extra letters. Lynette reached its peak popularity in English-speaking countries through the mid-twentieth century, giving it a warm retro quality today. It is neither old enough to feel antique nor recent enough to feel trendy — it exists in a pleasant intermediate zone that often appeals to parents fond of names with literary pedigree. Its Welsh roots add a Celtic depth, and the Arthurian association gives any Lynette a quietly legendary inheritance to grow into.