Synonyms:
observer, commentator
Meaning: an expert who observes and comments on something
Usage examples
The greatest observer and commentator upon manners that ever wrote was Mr. Emerson.
The Commentator held that this union is through the intelligible species, as having a double subject, in the possible intellect, and in the phantasms which are in the corporeal organs.
But if I admire the interpretation and that alone, what else have I turned out but a mere commentator instead of a lover of wisdom?--except indeed that I happen to be interpreting Chrysippus instead of Homer.