Although the Celebrity was almost impervious to sarcasm, he was now beginning to exhibit visible signs of uneasiness, the consciousness dawning upon him that his eccentricity was not receiving the ovation it merited.
More Examples
Used in the Middle of Sentence
The policeman decided to act upon the basis of his informants phone call
Objection is sometimes offered to this system upon the hypothesis that all but the rich or fullhanded, are excluded from our sanctuaries.
Let America add Mexico to Texas, and pile Cuba upon Canada; let the English overswarm all India, and hang out their blazing banner from the sun [ …] — Herman Melville, Moby-Dick.
Used in the Beginning of Sentence
Upon arrival at the campsite, they discovered that they had forgotten the tent pegs and had to use rocks and logs to tether the tent instead.
Upon the occasion of his first publication he quit his day job, only to find that Grub Street wasn't lined with manors and villas but hovels and slums.
Upon a hanging ledge of rock unstable, / Th' unsurest spot that may in earth be found, / Showing to all that she is never stable.
Used in the Ending of Sentence
Baiting fish is not illegal in this state, but strongly frowned upon.
Because of the professor's venerability his opinion was often asked, but his actual attendance in committee meetings was not insisted upon.
Meaning of upon for the defined word.
Grammatically, this word "upon" is an adverb, more specifically, an uncomparable adverb. It's also a preposition.