The slang term to describe a person’s facial appearance or personality is derived from the eighteenth century method for determining the nationality of a ship from a distance. This was done by checking the number and shape of its jib sails. For instance French ships often had two small jibs whereas Spanish ships had one small jib or none at all.
Jib was also sailors slang for face and therefore someone saying 'I dont like the cut of his jib' could mean they were suspicious of them.
CUT OF HIS JIB
