subgroup

American  

[suhb-groop] / ˈsʌbˌgrup /

noun

1. a subordinate group; a division of a group.

2. Chemistry. a division of a group in the periodic table.

3. Mathematics. a subset of a group that is closed under the group operation and in which every element has an inverse in the subset.

---

subgroup British  

/ ˈsʌbˌɡruːp /

noun

1. a distinct and often subordinate division of a group

2. a mathematical group whose members are members of another group, both groups being subject to the same rule of combination

---

Etymology

Origin of subgroup

First recorded in 1835–45; sub- + group

Example Sentences

"There was recognition that there is a very small subgroup of children whose gender incongruence persists long-term and who may require ongoing support and possible medical interventions," the review said.

From BBC • Feb. 10, 2026

The second subgroup, CD16+CD56high cells, is less common and contributes to the release of proteins that act as chemical messengers and support immunoregulation.

From Science Daily • Dec. 15, 2025

The subgroup of panel members that recommended the change also said it understood that “the safety concern may be more theoretical than real.”

From The Wall Street Journal • Dec. 6, 2025

Fernandez said he was not in a deputy gang or problematic subgroup.

From Los Angeles Times • Jun. 6, 2025

As a subgroup, relos are economically homogenous, with midcareer incomes starting at $100,000 a year.

From "Class Matters" by The New York Times