niche
Definitions
A specialized segment of the market for a particular kind of product or service.
A comfortable or suitable position in life or employment.
A shallow recess, especially one in a wall to display a statue or other ornament.
Examples
She has carved out a successful niche for herself in the competitive world of freelance graphic design.
The company decided to focus on a small market niche that larger competitors had largely ignored.
He finally found his niche as a historical researcher after years of working in unrelated fields.