in group, in-group n. An exclusive circle of people with a common purpose, interests, or attitudes, especially one that produces feelings of camaraderie, exclusivity, community, and solidarity.
... esteemed it a great compliment to be asked, but all expected to be paid for it. And if anything were wanting to complete our opportunities for gaining all information that was of interest, we found it in the daguerreotype. Captain E., knowing they were about to celebrate a feast he wished to paint in group, took his apparatus out, and, when they least expected it, transferred the group to his plate. The awe, consternation, astonishment and admiration, surpassed description. "Ho! ... — Dahcotah - Life and Legends of the Sioux Around Fort Snelling • Mary Eastman
... members of Group II the wings are almost entirely absent or "vestigial". This condition arose at a single step and breeds true, although it appears to be influenced to some extent by temperature, also by modifiers that sometimes appear in the stock. Purple eye color belongs in Group II; it resembles the color of the eye of the wild fly but is darker ... — A Critique of the Theory of Evolution • Thomas Hunt Morgan