(countable, slang) A dog of miscellaneous ancestry; a mutt. / (uncountable, poker) A variety of draw poker in which 5s and 7s are wild cards.

(of a thing) Being a complete mix; containing parts of many different origins. / (informal, of a person or animal, chiefly a dog) Having ancestry of many different origins; to be of mixed race or breed.

(physics) A minor stable isotope of iron, ⁵⁷₂₆Fe, having 26 protons and 31 neutrons; it amounts to about 2% of the element in nature

plural of 57-cell

plural of Heinz 57

(mathematics) Synonym of pentacontaheptachoron