Entirely
Part of speech: adverb
Definition: to the full or entire extent to the exclusion of others
Example sentence: Leave the matter of religion to the family altar, the church, and the private school, supported entirely by private contributions. Keep the church and state forever separate.
Solely
Part of speech: adverb
Definition: In a single, sole manner.Alone; exclusively.
Example sentence: God's the final judge for Elvis Presley and Johnny Cash too. That's solely in the hands of God.