A hand held up showing its palm. May be used to mean stop, or as a high-five.
It is also used instead of a greeting or as a part of it. Its other common meaning is connected to a gesture of raising a hand, which is commonly used by??Students in?Schools — i.e. as a sign that the user is eager to say something or to ask something important. In this sense, quite often, it has an ironic connotation.
Raised Hand was approved as part of Unicode 6.0 in 2010 and added to Emoji 1.0 in 2015.
U+270B
✋ Raised hand