Is it ensure, insure, or assure?
from Old English gang "a going, journey, way, passage," and Old Norse gangr "a group of men, a set," both from Proto-Germanic *gangaz (cf. Old Saxon, Old Frisian, Danish, Dutch, Old High German, German gang, Old Norse gangr, Gothic gagg "act of going"), from PIE root *ghengh- "to step" (cf. Sanskrit jangha "shank," Avestan zanga- "ankle," Lithuanian zengiu "I stride"). Thus not considered to be related to go.
The sense evolution is probably via meaning "a set of articles that usually are taken together in going" (mid-14c.), especially a set of tools used on the same job. By 1620s this had been extended in nautical speech to mean "a company of workmen," and by 1630s the word was being used, with disapproving overtones, for "any band of persons traveling together." Gangway preserves the original sense of the word, as does gangplank.
1856, from gang (n.). Related: Ganged; ganging. To gang up (on) is first attested 1919.
a group of persons, usually youths, who share a common identity and who generally engage in criminal behaviour. In contrast to the criminal behaviour of other youths, the activities of gangs are characterized by some level of organization and continuity over time. There is no consensus on the exact definition of a gang, however, and scholars have debated whether the definition should expressly include involvement in crime. Some gangs, but not all, have strong leadership, formalized rules, and extensive use of common identifying symbols. Many gangs associate themselves with a particular geographic area or type of crime, and some use graffiti as a form of nonverbal communication