What is the word that means "not able to be escaped from by struggling"?I heard it many years ago and have forgotten it due to advancing age and mis-spent youth.

Forgive me if I am not following the protocols of this site-I have just stumbled upon it. Also I am an Australian which explains many of the situations I find myself Faux Pas-ed within.

Thanks,

David

What is the word that means "not able to be escaped from by struggling"? I heard it many years ago and have forgotten it due to advancing age and mis-spent youth.