The name Blythe is a girl's name of English origin meaning "happy, carefree". Blythe and is often added to lists like One-Syllable Middle Names for Girls and discussed in our forums with posts like "What would be the perfect twin?".
From the experts:
Blythe embodies a cheerful, carefree spirit and could be the next Blair/Blaine/Blake/Brett/Britt, with the advantage that it's clearly pink. It joins other other light-hearted names for girls: Felicity, Hilary.
Blythe is the middle name of Drew Barrymore--in her case a surname from her rich theatrical history.
The title of the memorable Noel Coward play Blithe Spirit is taken from Shelley's poetic line, "Hail to thee, blithe Spirit"--a nice tribute to a baby Blythe.