nidi

1. a place in which bacteria have multiplied or may multiply; a focus of infection.

   abscesses and scarring were present which would be consistent with an initial nidus of infection in the lung

2. a place or situation in which something develops or is fostered.

   many models of society see the main nidus of struggle residing in the sphere of production

late 17th century (in the former sense ‘place in which an insect deposits its eggs’): from Latin, literally ‘nest’.