As used in sections 28-312 to 28-315, unless the context otherwise requires:
(1) Restrain shall mean to restrict a person's movement in such a manner as to interfere substantially with his liberty:
(a) By means of force, threat, or deception; or
(b) If the person is under the age of eighteen or incompetent, without the consent of the relative, person, or institution having lawful custody of him; and
(2) Abduct shall mean to restrain a person with intent to prevent his liberation by:
(a) Secreting or holding him in a place where he is not likely to be found; or
(b) Endangering or threatening to endanger the safety of any human being.