副詞 doubtless:

1. with certainty
   同義詞：undoubtedly, beyond question, without doubt, beyond any doubt

1. The Recording Angel responsible for the world of letters still doubtless raises an eyebrow at the curious company some good writing keeps.
   負(fù)責(zé)記錄文學(xué)界事務(wù)的天使對(duì)于那些與某些好作品相伴而生的稀奇古怪難以理解的東西仍無疑感到驚奇。
2. I shall doubtless see you tomorrow.
   我大概明天會(huì)見到你。
3. John will doubtless come early as he always does.
   約翰無疑會(huì)像平時(shí)一樣很早就來。

doubt.less

adv.（副詞）
Certainly:
無疑地，肯定地：
例句：
The wind was doubtless a factor.
無疑地，風(fēng)是一個(gè)因素

Presumably; probably:
假定地；很可能地：
例句：
as you doubtless already know.
正如你很可能早已知道的那樣

adj.（形容詞）
Certain; assured.
無疑的；肯定的

【引伸】
doubt.lessly
adv.（副詞）