1.【口】男人;傢伙;人

A fellow must eat.

人總得吃飯。

2.(大學的)研究員;(學術團體)會員

3.夥伴;同事

They are my fellows at school.

他們是我的同學。

4.【口】男朋友

5.一對中之一,配對物

.(可用作稱呼)朋友,友人

He is a close friend of mine.

他是我的摯友。

2.贊助者;支持者[(+of/to)]

That rich lady is a friend of the arts.

那位富婆是藝術的贊助者。

3.同胞;同伴

4.(經常遇見的)陌生人

基本上無大區別。但是在正式英語如填表格，只能用ancestor。forefather通常用於描述某某團體的創始人。

forefather

n.

An ancestor.

祖先

See: ancestor

A person who is from an earlier time and has originated or contributed to a common tradition shared by a particular group.

先人生活在較早時代並且開創了某一特定集體的共同傳統或為此作出了貢獻的人

ancestor

n.

A person from whom one is descended, especially if more remote than a grandparent; a forebear.

祖先，祖宗繁衍後代的人，特別是遠於祖父輩；前輩

A forerunner or predecessor.

前人，先驅先行者或先驅

形容詞 a.

1.同伴的;同事的;同類的[B]

He recalled his fellow traveller with pleas

基本上無大區別。但是在正式英語如填表格，只能用ancestor。forefather通常用於描述某某團體的創始人。

forefather

n.

An ancestor.

祖先

See: ancestor

A person who is from an earlier time and has originated or contributed to a common tradition shared by a particular group.

先人生活在較早時代並且開創了某一特定集體的共同傳統或為此作出了貢獻的人

ancestor

n.

A person from whom one is descended, especially if more remote than a grandparent; a forebear.

祖先，祖宗繁衍後代的人，特別是遠於祖父輩；前輩

A forerunner or predecessor.

前人，先驅先行者或先驅

我只能解釋這麼多了，後兩組的區別應該就是我寫的這麼多，你真的沒必要太鑽的。