1.
close, intimate, closely connected, closely related
Having a very close connection or relationship between things, concepts, or people. Often used to describe abstract relationships rather than physical proximity.
Usage
Primarily used for abstract relationships between concepts, fields, or organizations rather than physical closeness. The adverbial form 密接に is very common. During the COVID-19 pandemic, 密接 gained additional prominence as one of the "three Cs" (三密): 密閉 (enclosed spaces), 密集 (crowded places), and 密接 (close contact).