Geez is defined as an exclamation you shout showing surprise or annoyance.
(interjection)When you are annoyed because your friend is late for the 10th time in a row, this is an example of when you might shout "Geez!"
See geez in Webster's New World College Dictionary
interjection
noun
See geez in American Heritage Dictionary 4
interjection
Origin:
Origin: Shortening and alteration of Jesus1
.