swear by 1. 以…发誓 He swore by his honour he would return the bike. 他以自己的名誉发誓保证归还自行车。 The witness swore by the Bible that he would tell the truth. 证人以《圣经》的名义起誓保证说实话。 2. 〈口〉极其信赖；经常使用；推荐 swear by one's doctor 极其信赖自己的医生 swear by Tamiflu for bird flu 极其相信达菲能治禽流感