出典:Wiktionary
From Middle English forthberen, possibly from 古期英語 forþberan (“to bring forth, produce”). Equivalent to forth- + bear. The Middle English word is alternatively a calque of Latin prōferre.
forthbear (third-person singular simple present forthbears, present participle forthbearing, simple past forthbore, past participle forthborne or (廃れた用法) forthborn)