A jib is the triangular sail that sticks out towards the front of a boat, and this seems to have led to its use to describe the human nose, or sometimes the lower lip when it's pushed out in a pout.
If you're lucky enough to be in South Wales, then making jibs is making faces.
Painting: Adriaen Brouwer
The jib of a crane is its sticky-out arm bit, which you'd think would be the same basic word as the sail word but might not be.
The cut of your jib is the general impression you give people. It's usually used negatively, and always (as far as I know) about a man: I don't like the cut of his jib.
A boat jibs when a sail shifts dangerously from one side of the vessel to the other; and if you're in Britain then jibbing at something is holding back from doing it. A horse that jibs at a fence refuses to jump it, and if someone asks you to do a tightrope walk, for instance, or a bank robbery, you might jib at that.
The thing you jib at is usually something scary but, even so, it's not always easy to be sure whether jibbing is a bad thing.
Except, naturally, in the case of the bank robbery.
Thing To Do (or not) Today: jib. The arm of the crane word may come from the word gibbet. As for the rest, everyone seems to be jibbing away from committing themselves.