Cut of your jib
One's general appearance and demeanour.
The jib of a sailing ship is a triangular sail set between the foretopmast head and the jib boom. Some ships had more than one jib sail. Each country had its own style of sail and so the nationality of a sailing ship, and a sailor's consequent opinion of it, could be determined from the jib.
The phrase became used in an idiomatic way during the 19th century. Sir Walter Scott used to it in St. Ronan's Well, 1824:
"If she disliked what the sailor calls the cut of their jib."
There may be an allusion between the triangular shape of noses and jibs in the figurative use of this phrase, but this isn't authenticated.
See other Nautical Phrases.
See also - phrases coined by Sir Walter Scott.