Which two phrases best helps determine the meaning of the word extricate?

Worsley, who had hung up his trousers and socks on a boat, found them iced-up and stiff; and it was quite a painful process for him to dress quickly that morning. I was anxious, now that we had started, that we should make every effort to extricate ourselves, and this temporary check so early was rather annoying. So that afternoon, Wild and I ski-ed out to the crack and found that it had closed up again.

1) "make every effort to extricate ourselves"

2) "had closed up again"