a small hole or surface on a rock that is just big enough for a climber to put the end of his or her foot in or on

I searched desperately for a toehold in the rock face. 我努力在岩石表面寻找立足点。

a strong first position from which further progress can be made

Insurance is a very difficult market to get a toehold in. 在保险市场中立足很难。