lecture vs tell off

lecture is a noun but tell off is not a noun.

Word	Noun	Adjective	Verb	Adverb
lecture	Yes	No	Yes	No
tell off	No	No	Yes	No

As verbs, tell off is a hyponym of lecture; that is, tell off is a word with a more specific, narrower meaning than lecture:

Other hyponyms of lecture include castigate, chasten, chastise, correct, objurgate, brush down.

lecture (noun)	tell off (noun)
teaching by giving a discourse on some subject (typically to a class)
a speech that is open to the public
a lengthy rebuke

lecture (verb)	tell off (verb)
censure severely or angrily	reprimand
deliver a lecture or talk