the.com/incubation

means The process of maintaining the right conditions over time so that something — an egg, an idea, an infection — can develop to the point of hatching, emerging, or becoming apparent.

from From Latin incubare, 'to lie upon,' built from in- ('on') plus cubare ('to lie down'). The Romans used it literally for hens brooding eggs, but also for a stranger ancient practice: sleeping in a temple in hopes the god would send a healing or prophetic dream — the sleeper 'incubating' a vision the way a hen incubates a chick. English kept the warming, waiting sense and later stretched it to diseases quietly developing in the body and ideas slowly developing in the mind.