at first 起先

同义词组： a head of 领先 at the outset 最初 above all 首先 begin with 首先 first and foremost 首先 first of all 首先 for one thing 首先 in the first place 首先 second to none 首屈一指 lead off 开始

反义词组：after all 最后 as it turn(s) out 最终证明为 at last 最后 at the end of the day 最终 once and for all 最后一次