* Llydia: This is the closest transliteration of "Lydia" into Welsh, keeping the original sound.
* Llwydwen: Meaning "grey-haired" or "grey-white," this name has similar sounds to "Lydia."
* Llinos: Meaning "linnet," this name has a similar soft, feminine feel to "Lydia."
* Llywelyn: This name means "lion-like" and may be a strong option if you want a name with similar energy to "Lydia."
Ultimately, the best way to choose a Welsh name for "Lydia" is to consider the meaning you want the name to have and the sound you prefer.