not old, has not existed for a long time
young
the direction in front of you
forward
the direction behind you
backward
unsafe, may cause serious injury or accident
safe
not difficult to understand or do
simple
very clever or smart, can understand complicated things
intelligent
silly and not very thoughtful
foolish
difficult to do or understand
complicated
not in a place or a class
absent
grown-up physically or mentally
mature
unsafe, may cause serious injury or accident
dangerous
at a place or in a class
present