cohortyoudaoicibaDictYouDict[cohort 词源字典]
cohort: [15] Etymologically, cohort is an ‘enclosed yard’. It comes via Old French cohorte from Latin cohors, a compound noun formed from the prefix com- ‘with’ and an element hortwhich also appears in Latin hortus ‘garden’ (source of English horticulture) and is related to English garden, yard, and the second element of orchard.

From the underlying sense of ‘enclosed place’ it came to be applied to a crowd of people in such a place, and then more specifically to an infantry company in the Roman army. Its meaning has spread figuratively in English to ‘band of associates or accomplices’, whose frequent use in the plural led to the misapprehension that a single cohort was an ‘associate’ or ‘accomplice’ – a usage which emerged in American English in the mid 20th century.

The original form of the Latin word is well preserved in cohort, but it has also reached us, more thickly disguised, as court.
=> court, garden, horticulture, orchard, yard[cohort etymology, cohort origin, 英语词源]
cohort (n.)youdaoicibaDictYouDict
early 15c., "company of soldiers," from Middle French cohorte (14c.) and directly from Latin cohortem (nominative cohors) "enclosure," meaning extended to "infantry company" in Roman army (a tenth part of a legion) through notion of "enclosed group, retinue," from com- "with" (see co-) + root akin to hortus "garden," from PIE *ghr-ti-, from root *gher- (1) "to grasp, enclose" (see yard (n.1)). Sense of "accomplice" is first recorded 1952, American English, from meaning "group united in common cause" (1719).