Friday word: Nidus

[med_cat]

ni·dus, noun \ˈnī-dəs\
plural ni·di or ni·dus·es

1: a nest or breeding place; especially : a place or substance in an animal or plant where bacteria or other organisms lodge and multiply
2: a place where something originates, develops, or is located

Example:

<a type of contact lens that proved to be a nidus of infection>

Etymology:
New Latin, from Latin
First Known Use: 1742