動詞 forswear:

1. formally reject or disavow a formerly held belief, usually under pressure
   同義詞：abjure, recant, retract, resile

1. He had forsworn smoking.
   他已經(jīng)戒煙了。

forswear 也作 fore.swear

v.（動詞）
for.swore[fôr-swôr., fôr-swôr.] for.sworn[fôr-swôrn., fôr-swôrn.] for.swear.ing,for.swears
v.tr.（及物動詞）

To renounce or repudiate under oath.
放棄，發(fā)誓拋棄
To renounce seriously.
堅決放棄
To disavow under oath; deny.
發(fā)誓否認(rèn)；堅決否認(rèn)
To make (oneself) guilty of perjury.
使犯偽證罪：因發(fā)偽誓而有罪
v.intr.（不及物動詞）
To swear falsely; commit perjury.
作偽證：發(fā)偽誓；作偽證

來源：
Middle English forsweren
中古英語 forsweren
from Old English forswerian
源自 古英語 forswerian
for- [wrongly] * see for-
for- [錯誤地] *參見 for-
swerian [to swear] * see swear
swerian [發(fā)誓] *參見 swear