the.com/offshoot

means A smaller group, organization, or thing that develops out of a larger one and grows into a distinct entity of its own.

from Straightforward compound: 'off' plus 'shoot,' in the botanical sense of a shoot that sprouts off a plant's main stem. The literal gardening word — a side-stem branching off the main one — got figurative legs, and by extension came to describe anything (a company, a movement, a dialect, a family line) that sprouted off some larger original and kept growing on its own.