A yellow face with frowned eyes, furrowed eyebrows, and a sad, open mouth. Often used to express exhaustion or groaning in exasperation.
It's similar to the 😩 Weary Face emoji in meaning and design(except for the eyes).
The Moan emoji also used as an expression of physical or mental suffering or sexual pleasure. Because of its wide-open 👄 mouth, it's occasionally used in a sexual context.
In most use cases, it conveys exhaustion, frustration, tiredness, or stress. The emoji is used the most on workdays when people are tired at work.