The name Briony is a girl's name of Latin origin meaning "to sprout". Briony and is often added to lists like Literary Names for Girls and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
Briony may be the variation and Bryony the original, but many parents will see this as the more authentic-feeling version of this attractive botanical name. Still unusual in the U.S., Briony is in the British Top 100 and may appeal to parents as a fresh spin on Briana or Brittany or an honorific for a Brian, though it bears no relationship to the male name.
Briony Tallis is the young girl who sets the plot in motion in Ian McEwan's novel Atonement--played on screen by Saoirse Ronan, for which she received a Best Supporting Actress Oscar nomination.
Briony is a variant spelling of Bryony, coming from the Greek meaning 'to grow luxuriantly'. Bryony/Briony is an unusually strong plant name --the bryony being a wild climbing vine with green flowers
Pronunciation is like Brian with an ee at the end.