Definition from Wiktionary, the free dictionary
circumoral (not comparable)
- around or encircling the mouth.
- You know this smile: the strenuous contraction of circumoral fascia w/ incomplete zygomatic involvement, the smile that doesn't quite reach the smiler’s eyes and that signifies nothing more than a calculated attempt to advance the smiler’s own interests by pretending to like the smilee. From: A Supposedly Fun Thing I’ll Never Do Again (1997) by David Foster Wallace, page 289.