1) Callowness 2) Childhood 3) Greenness 4) Immatureness 5) Imperfection 6) Incompleteness 7) Jejuneness 8) Juvenility 9) Newness 10) Nonage 11) Prematureness 12) Prematurity 13) Puerility 1) Immatureness 2) Infantile behaviour 3) Irresponsibility 4) Juvenile behaviour 5) Not having reached maturity 6) Pettiness 7) Silliness 8) State 
• (n.) The state or quality of being immature or not fully developed; unripeness; incompleteness.
the state or quality of being unripe or not fully developed.
(from the article `sedimentary rock`) Immature sandstones contain a clay matrix, and the sand-size grains are usually angular and poorly sorted. This means that a wide range of sand sizes ...
The state or quality of being unripe or not fully developed. ... (18 Nov 1997) ... 
Im`ma·tu'ri·ty noun [ Latin immaturitas : confer French immaturité .] The state or quality of being immature or not fully developed; unripeness; incompleteness. « When the world has outgrown its intellectual immaturity .» Caird. 
[n] - not having reached maturity
a state or condition of being immature: the immaturity of one's behavior; the immaturity of a country's technology. · an immature action or attitude.