Sentence:  The content of his words may lapse back into monotonous repetition , as if a phonograph needle were stuck in one groove ; only seldom is it so simple as to be a matter of his obviously parroting some timeworn axiom , common to our culture , which he has evidently heard , over and over , from a <WSD>parent</WSD> until he experiences it as part of him . 
Meaning of the word marked with <WSD> tags:  a father or mother; one who begets or one who gives birth to or nurtures and raises a child; a relative who plays the role of guardian