(algebraic topology) The kernel of the kᵗʰ boundary homomorphism (of a given chain complex).

plural of hate group

A social group that advocates and practices hate speech and/or hate crimes.

plural of wallpaper group

(geometry) A mathematical group that classifies two-dimensional repeating patterns based on their symmetries.

(education, historical) A system of children's education in which one group studied while another group carried out activities.

plural of stem group

Alternative form of regroup.

plural of main group

(taxonomy) Sometimes used to indicate that a formerly accepted taxonomic group is considered not to be paraphyletic or polyphyletic