D defs.my
Entry 3 senses Webster, 1913

Incubate

/ĭn'-kyəb-ātˌ/ · In·cu·bate · IPA /ˈɪŋkjʊbeɪt/
01 v. i. & t. To sit, as on eggs for hatching; to brood; to brood upon, or keep warm, as eggs, for the purpose of hatching.
imp. & p. p. Incubated; p. pr. & vb. n. Incubating
  1. 1.
    To sit, as on eggs for hatching; to brood; to brood upon, or keep warm, as eggs, for the purpose of hatching.
  2. 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. 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.