raised hand

Stop / halt — an open palm held up meaning "stop," "wait," or "that's enough."

High five — a raised flat palm offered to slap against another's in celebration, greeting or congratulations ("up top!").

Raise your hand / volunteer / "present" — hand up to ask to speak, answer, volunteer, or mark attendance: "me!" / "I'll do it."

"Talk to the hand" / dismissal — palm thrust toward someone to reject or silence them, a contemptuous 1990s brush-off.