Other forms: somewheres
The adverb somewhere means "in an indefinite location." If your parents promise you're going somewhere for spring break, you know you'll be traveling but you don't know the exact destination. Let's hope it's not another trip to visit the Museum of Yarn.
If your brother wants to go somewhere warm in January, but you'd rather head somewhere with good skiing, you'll have to work on a compromise. Neither of you has a definite place in mind, so you may be able to work it out. When Dorothy wished she could travel somewhere over the rainbow, she wasn't specifically imagining the Land of Oz. You can also substitute the informal someplace for somewhere.