Yes. As Enmos said, via dictionary (or as the dictionary said, via Enmos?), theism is simply the belief in god or gods.
In short, it is a theological stance, irrespective of religion, that demonstrates belief in deity. The only other stance is atheism. Agnosticism pertains, not so much to belief, but knowledge, hence "gnos" in the middle of it. You can be an agnostic theist just as much as you can be an agnostic atheist.
And theism is not restricted to monotheism. That is but on sub-category within theism. There is also polytheism, deism, henotheism, etc.
Pantheism and animism fall somewhere in between, interestingly. So I guess my previous statement of there only being atheism/theism stances is a tad inaccurate. There is a somewhat grey area betwixt wherein lies pantheism and animism.