From telos; complete (in various applications of labor, growth, mental and moral character, etc.); neuter (as noun, with ho) completeness -- of full age, man, perfect.
KJV: Jesus said unto him, If thou wilt be perfect, go and sell that thou hast, and give to the poor, and thou shalt have treasure in heaven: and come and follow me.
NASB: Jesus said to him, "If you wish to be complete, go and sell your possessions and give to the poor, and you will have treasure in heaven; and come, follow Me."
KJV: And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
NASB: And do not be conformed to this world, but be transformed by the renewing of your mind, so that you may prove what the will of God is, that which is good and acceptable and perfect.