不屈不挠
Stick to one's colours.
Firm and unyielding.
Fight for it tooth and nail.
Hang on by the eyelashes.
Keep one's chin up.
As steady as a rock.
eg:To gain confidence of others for your idea, you have to stick to your colours.
中英俚语俗语来源:汉书·叙传下:“乐昌笃实,不挠不屈。”
同义词:百折不挠 Stick it out.
反义词:俯首就范 Give one's head for the washing.