Incubate
Incubate , verb, intransitive and transitive
[Latin incubatus, p. p. incubare to lie on; pref. in- in, on + cubare to lie down. Compare Cubit, Incumbent.]
1.
To sit, as on eggs for hatching; to brood; to brood upon, or keep warm, as eggs, for the purpose of hatching.
2.
To maintain (a living organism, such as microorganisms or a premature baby) under appropriate conditions, such as of temperature, humidity, or atmospheric composition, for growth; as, coliform bacteria grow best when incubated at 37° C..
3.
To develop gradually in some interior environment, until fully formed; as, the ideas for his book were incubating for two years before he began to write.