It is a small hill.
The nerve cell hillock is the beginning of the axon immediately after the soma. This is where the action potential originates.
The function of the axon hillock is to initiate the propagation of the action potential down an axon.
noun: a small hill; mound. Example sentences: We found it a tad difficult to climb the rocky hillock. When we finally got to the top of the hillock, we saw lots of sheep. There was beautiful scenery...
axon hillock is the part of a cell