Definition of Cranial nerve, first

Cranial nerve, first: The cranial nerves emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves.

The first cranial nerve is the olfactory nerve which carries impulses for the sense of smell from the nose to the brain.

The word "olfactory" comes from the Latin "olfactare", to sniff at and "olfacere", to smell.