asterismPronunciation: /ˈastərɪz(ə)m/Definition of asterism noun 1 Astronomy a prominent pattern or group of stars that is smaller than a constellation. 2a group of three asterisks (⁂) drawing attention to a piece of text. Origin: late 16th century: from Greek asterismos, from astēr 'star'asterism in other Oxford dictionaries Definition of asterism in the US English dictionary