(group theory) A group whose elements represent ways to weave some number of strings into braids.

(group theory) Any one of the 26 exceptional finite simple groups, which do not belong to any of the general, infinite categories specified by the classification theorem for finite simple groups.

(group theory) A group generated by a single element.

(dated, psychotherapy) A gathering of people who intentionally meet and interact so that each member may improve his or her ability both to express feelings and to react with appropriate sensitivity to the feelings of others.

(inorganic chemistry) Group 3 of the periodic table, comprising scandium, yttrium, lanthanum and actinium.

(inorganic chemistry) Group 4 of the periodic table, comprising titanium, zirconium, hafnium and rutherfordium

(inorganic chemistry) Group 5 of the periodic table, comprising vanadium, niobium, tantalum and dubnium

(inorganic chemistry) Group 6 of the periodic table, comprising chromium, molybdenum, tungsten and seaborgium

(inorganic chemistry) Group seven of the periodic table, comprising manganese, technetium, rhenium and bohrium.

(inorganic chemistry) Group 8 of the periodic table, comprising iron, ruthenium, osmium and hassium