the GNU version of the Collaborative International Dictionary of English
adj. Of or pertaining to incubation, or to the period of incubation.
The Century Dictionary and Cyclopedia
Of or pertaining to incubation or the period of incubation; of the nature of incubation; in pathology, relating to the period during which a disease is supposed to be hatching in the system before manifesting itself.
Word Usage
"That the so-called incubative period is very definite and regular, being just a fortnight from infection to eruption."