To prevent or discourage from acting, as by means of fear or doubt: threats that did not deter her from speaking out; skin chemicals that deter predators.

What does deter from mean?

transitive verb. 1 : to turn aside, discourage, or prevent from acting she would not be deterred by threats. 2 : inhibit painting to deter rust.

What is to deter?

verb (used with object), de·terred, de·ter·ring. to discourage or restrain from acting or proceeding: The large dog deterred trespassers. to prevent; check; arrest: timber treated with creosote to deter rot.