Is it acceptable to paraphrase or include reviewer's comments in revised manuscript?
It would be acceptable to paraphrase the referee's comments, although if you do so, you should take care.  First, the paraphrasing should be thorough.  You cannot quote an anonymous* referee directly (since you do not know their identity to cite them), so what you put in your revised draft should not include any specific extended phrases used by the reviewer, of the kind that would normally need quotation makes.

Second, you should point out explicitly in your reply letter with the revised manuscript that you have followed the referee's way of describing the subject matter carefully.  Make it clear that you have done so because you though the explanation in the referee's report was exceptionally clear.  The referee is likely to be flattered, but in the unlikely event that they have some problem with your having done this, they have been warned and can ask you to make further changes.

Third, you should include an acknowledgement to the anonymous reviewer.  This person has made a minor but specific contribution to your paper and deserves credit at that level.

*I have assumed the reviewer is anonymous.  If not, things probably do not change very much, although you have the option of simply contacting the reviewer to ask whether they are okay with you paraphrasing them this way.