fear
Fear is a strong and unpleasant emotion that we feel when we are in danger.
fever
A fever is a reaction to an illness or virus that causes your body temperature to rise and makes you feel very hot.
flu
Flu is a contagious respiratory disease caused by a virus that can enter the body through the nose or mouth.
fracture
A fracture is a crack or break in a part of the body, such as a bone, ligament (which connects bones to joints), tendon (which connects bones to muscles), that hurts a lot.
fright
See fear.