Posting on X, Gloucester said: “A true Cherry & White legend calling it a day. Thanks for all the memories, Billy.”
At Trailfinders he was part of the first team outside the top flight to reach a Premiership Rugby Cup semi-final, as well as winning the second-tier title.
“Although we only had Billy with us for a year, he made a big impact on our squad. His career speaks for itself and he can be incredibly proud of all that he has achieved,” Ealing director of rugby Bill Ward told the club’s website., external
“We will miss him as a player, but more than that he is one of the good guys and a really good bloke that we will miss even more.
“We wish him all the best for the future.”