gut it out

Reader's　Digest 9月号の記事 "Between a Rock and a Hard Place" の副題からの引用です。

Pinned by a giant boulder, a hiker had two choices: panic or gut it out. He did both.

"gut it out" が分かりません。辞書を見ます。

・Oxford English Dictionary: to work very hard to achieve something: I slogged my guts out for the exam.
・Collins Dictionary: If you say that you are working your guts out or slogging your guts out, you are emphasizing that you are working as hard as you can.: [informal, emphasis] Most have worked their guts out and made sacrifices.
・Cambridge English Dictionary: to work extremely hard: I've been working my guts out these past few weeks and all he can do is criticize.
・Farlex Dictionary of Idioms: To endure or tolerate some task or activity despite pain, hardships, or unpleasant conditions. Used especially in reference to sports. A noun or pronoun can be used between "guts" and "out.": I'm surprised the captain gutsed out the entire season with that injury.