Linear means in a straight line. It's different from curved. Depending on the subject and the age of the kid to whom I'm being friendly, it might also mean an algebra equation that includes y and x, but not x squared or y cubed, etc.
"Linear means that things are in a straight line, like when you connect dots from one to the next without any curves or bends."
A kid friendly definition of the word energy is, the ability to do work.
a kid friendly definition would be two or more people that disagree on something and are not getting along.
changing
competition
A kid friendly definition of disease would be "a very serious sickness a person/people could catch or already have from their parents.
Something that someone has to do.
A kid friendly definition would be - The head of the Catholic Church.
rights for a civallion
A course of action determined or decided on.
A final urgent demand.
look at me, pay attention
reliable, mature, honest, answerable, dutiful