That could be several things:
The English root is protect. (There is no English root *tect).
The opposite of protect is attack.Attack, harm, hurt, injure...
skull protects the brain
protect
protect
Security means freedom from danger or threat.
to harm
causing harm or damage
The root word for "harm" is "hama" from Old Norse meaning "grief" or "sorrow."
Yes, protect, meaning to keep safe from harm, is an action and therefore a verb.A verb is a word that describes an action (run, walk, etc), a state of being (exist, stand, etc) or occurrence (happen, become, etc).
False is a five letter word meaning fake.
A four letter word meaning not kosher is: tref