To whicker is to make a soft neighing sound. The horse whickered at the gate.
It is the quiet greeting sound rather than any alarm, which is what separates it from a neigh. A horse will whicker at somebody it knows and at nobody else.
1verbwhickerTo make a soft neighing sound.
“The mare would whicker whenever she heard the bucket.”
whicker is a sound.
Also accepted in games: whinny
Practised in A Song of Ice and Fire