by one supreme effort to win eternal ease—settle a matter once and for all;do it (/away with the trouble) for good; do sth well so that one never has to do it again; get sth done(/put sth right)once and for all; work out sth efficacious for ever ❍ 为了～，最后我决定，把太监全都赶走不要！ (爱新觉罗·溥仪《我的前半生》150) Finally I decided to deal with the problem once and for all by expelling all the eunuchs from the palace. ❍ 自买印刷机，才是～的办法呢。(李六如《六十年的变迁》Ⅰ—171)To buy a press of our own is the only way to get rid of such trouble once and for all.
一劳永逸
achieve a permanent fix; achieve a permanent solution;settle sth once and for all
一劳永逸yī láo yǒnɡ yì
费一次劳力就永得安逸。get sth. done once and for all, do it for good, once and for all, for good (and all), hold good for all times