astroid /asˈtroid/ (mathematics)

A hypocycloid with four cusps

• turn on one's heel
• turn on the heat
• turn out
• turnout
• turnouts
• turn over
• turnover
• turn over a new leaf
• turnovers
• turnover tax
• turnover taxes
• turn-penny
• turnpike
• turnpike man
• turnpike men
• turnpike road
• turnpike roads
• turnpikes
• turnpike stair
• turn Queen's evidence
• turn round
• turnround
• turnrounds
• turns
• turn-screw