further along in progress than others
They developed an advanced form of communication.

the state or period of being a child
My childhood was full of wonderful memories of trips to the park.

difficult to do, deal with, or understand
Men are more complicated than they think.

dealing with facts and certainties
The police did not have any concrete evidence to arrest the criminal.

something that tells you what someone or something is like
I gave a good description of the car I saw speeding away from the accident.

third stage of development where children understand more things especially math
At the operational stage, children can understand things from another person's perspective.

the second developmental stage where a child begins to understand many things but still makes many mistakes
Children begin to use simple language in the preoperational stage.

reasonable or logical
He took the job that seemed the most sensible for him.

the first stage of mind development where the senses are used to ascertain things
Babies utilize sensorimotor in a stage that is dominated by the senses.

very lean or thin
Because it had no one to take care of it, the skinny dog lived on the street.