Gwillym moelelo wa lebitso le letle: Ela hloko, Mehleng ea kajeno, Bōpo, E fokolang, E thabileng. Fumana Gwillym moelelo oa lebitso.
Hilt lebitso la motumo o motle ka ho fetisisa: E na le bokhoni, Botsoalle, E tebileng, E thabileng, E fokolang. Fumana Hilt se boleloang ke lebitso.
Gwillym tšimoloho ea lebitso la pele. Welsh form of William. Fumana Gwillym tšimoloho ea lebitso la pele.
Gwillym lebitso la diminuti: Gwil. Fumana Mabitso a marang-rang a Gwillym.
Mabitso a sa tšoaneng bakeng sa Gwillym linaheng le lipuo tse sa tšoaneng: Bill, Billie, Billy, Guglielmo, Guilherme, Guillaume, Guillem, Guillermo, Gwilherm, Illiam, Jami, Jelle, Liam, Pim, Uilleag, Uilleam, Uilliam, Ulick, Vilĉjo, Vilém, Vilhelm, Vilhelmas, Vilhelmi, Vilhelmo, Vilhelms, Vilhjálmur, Vilho, Vili, Viliam, Vilim, Vilis, Viljami, Viljem, Viljo, Vilko, Ville, Villem, Vilmos, Wil, Wilhelm, Wilhelmus, Wilkin, Wilky, Will, Willahelm, Willem, Willi, William, Willie, Willy, Wilmot, Wim, Wiremu, Wöllem, Wullem, Wum. Fumana Gwillym ka lipuo tse ling.
Mabitso a tloaelehileng ka lebitso la ho qetela Hilt: William, Stephen, Robyn, Duane, Joseph. Fumana Mabitso a tsamaeang le Hilt.
Ho lumellana ha Gwillym le Hilt ke 83%. Fumana Tšebelisano ea Gwillym le Hilt.