The full sentence is 「ちょっと こいや」.
It's not a word on its own, but a combination of 来い (imperative "come") and や (see #3 in this dictionary entry).
As l'électeur pointed out in the comments, it can be understood as a "tough guy's imperative."
As l'électeur said, it definitely shows tough guy's commanding nature. For example consider the following statement:
Forget your troubles for a while and come and have dinner with us.
In the statement above
ちょっくら means a little
晩飯 or ばんめし means dinner
食い or くい means eating
As you can understand from the context, the speaker's statement has somewhat demanding/commanding nuance attached to it. I think if you understand the nuance, you will understand how and when to use it.