Is it farther or further?
1640s, "to brood upon, watch jealously" (which also was a figurative sense of Latin incubare); 1721 as "to sit on eggs to hatch them," from Latin incubatus, past participle of incubare "to lie in or upon" (see incubation). Related: Incubated; incubating.
incubate in·cu·bate (ĭn'kyə-bāt', ĭng'-)
v. in·cu·bat·ed, in·cu·bat·ing, in·cu·bates
To maintain eggs, organisms, or living tissue at optimal environmental conditions for growth and development.
To maintain a chemical or biochemical system under specific conditions in order to promote a particular reaction.