1. A specialized subject or theme that appeals to or interests a specific, limited audience rather than the general public
The podcast focuses on a niche topic that only appeals to vintage car enthusiasts.
O podcast se concentra em um tópico de nicho que só interessa a entusiastas de carros antigos.
2. A particular area of interest or expertise that serves a narrow market segment
She started a blog about a niche topic: rare orchid cultivation.
Ela começou um blog sobre um tópico de nicho: cultivo de orquídeas raras.