1 [with object] (of a bird) sit on (eggs) in order to keep them warm and bring them to hatching. (in a laboratory or other controlled situation) keep (eggs, bacteria, embryos, etc.) at a suitable temperature so that they develop: the samples were incubated at 80°C for 3 minutes North American give support and aid the development of (a new small business).
(be incubating something
) be developing an infectious disease before symptoms appear:the possibility that she was incubating early syphilis
[no object] develop slowly without outward or perceptible signs:the BSE bug incubates for around three years