Answer:

coset

Answer	Crossword Clue
COSET	Math subgroup
COSET	Mathematical grouping
COSET	Mathematical subgroup

COSET	Corresponding set: Math.
COSET	Algebraic grouping
COSET	"Left" or "right" group, in math
COSET	Subdivision in group theory

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.