Zygomaticous

The lexeme "zygomaticous" is semantically encapsulated within the realm of facial anatomy, specifically signifying the zygomatic muscles, intrinsically tasked with the dynamic modulation and regulation of the bilateral osseous prominences known as the cheekbones. Etymologically rooted in the adjective "zygomatic," pertinently linked to the zygoma—an osseous arch delineating the cheekbone—the term "zygomaticous" intricately delves into the domain of facial physiology, elucidating the multifaceted role of the aforementioned muscles in orchestrating and finely tuning facial expressions, with a particular emphasis on those emotive gestures associated with the act of smiling.

"After telling the amusing story, his zygomaticous muscles contracted, creating a cheerful and infectious smile that lit up the entire room."

"As the comedian delivered his punchline, the audience erupted into laughter, and the zygomaticous muscles of many attendees were engaged, reflecting the joyous atmosphere in the room."

"Her zygomaticous muscles twitched into action as she shared a delightful moment with her friends, their laughter echoing in the air."