Gwillym moelelo wa lebitso le letle: Ela hloko, Mehleng ea kajeno, Bōpo, E fokolang, E thabileng. Fumana Gwillym moelelo oa lebitso.
Pietrzak lebitso la motumo o motle ka ho fetisisa: Botsoalle, E na le bokhoni, Ela hloko, Mehleng ea kajeno, Bohale. Fumana Pietrzak 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.
Lebitso la ho qetela Pietrzak le tloaelehileng haholo Poland. Fumana Pietrzak lebitso la lebitso le fetisetsang.
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 Pietrzak: Theresa, Chet, Belkis, Ryann, William. Fumana Mabitso a tsamaeang le Pietrzak.
Ho lumellana ha Gwillym le Pietrzak ke 78%. Fumana Tšebelisano ea Gwillym le Pietrzak.