Pertaining to a hydrocarbon source rock that has not fully entered optimal conditions for generation.

1behaving in a way that is not sensible and is typical of people who are much younger immature behavior2not fully developed or grown immature plants opposite mature  immaturity  jump to other results [..]

1540s, "untimely, premature," from Latin immaturus "untimely, unripe," from assimilated form of in- "not, opposite of" (see in- (1)) + maturus "ripe, timely, early&q [..]

An immature bird is a juvenile that has undergone its first moult but does not yet have full adult plumage.

characteristic of a lack of maturity; "immature behavior" young: (used of living things especially persons) in an early period of life or development or growth; &quot [..]

not mature, premature, Not perfect

adj. Not full-grown.

 lacking complete development; not yet adult. This life stage for a spider means that the genitalia are not developed enough yet to even determine the gender of the specimen. This term is interchangeable with ‘juvenile’ or ‘sub-adult.’

(adj) characteristic of a lack of maturity(adj) (used of living things especially persons) in an early period of life or development or growth(adj) not fully developed or mature; not ripe(adj) not yet [..]

a young bird that is not fully adult (not being cared for by the parents, but not old enough to breed.) For bird banding, a young bird capable of sustained flight known to have hatched during the same [..]

not mature, unripe, not arrived at perfection of full development

adult past teneral stage but still not with mature coloration; usually not at water

an organism that is not fully developed and not reproductively capable

not mature or ripe; any arthropod stage not in the reproductive mature form

Not fully formed or developed, unripe, not mature. Childish in behavior, not mature. ''You're only young once, but you can be immature the rest of your life.'' ''The man was immature for throw [..]