A yell, shout.
I heard a holler from over the fence.
By extension, any communication to get somebody's attention.
If you need anything, just give me a holler.
To yell or shout.
You can holler at your computer as much as you want, but it won't help anything.
To call out one or more words
To complain, gripe
A small valley between mountains.
He built himself a cabin in a hollow high up in the Rockies.
A sunken area or unfilled space in something solid; a cavity, natural or artificial.
the hollow of the hand or of a tree
A sunken area.
A feeling of emptiness.
a hollow in the pit of one's stomach
(of something solid) Having an empty space or cavity inside.
a hollow tree; a hollow sphere
(of a sound) Distant, eerie; echoing, reverberating, as if in a hollow space; dull, muffled; often low-pitched.
He let out a hollow moan.
Without substance; having no real or significant worth; meaningless.
a hollow victory
Insincere, devoid of validity; specious.
a hollow promise
Concave; gaunt; sunken.
Pertaining to hollow body position