teach vs lecture

teach is not a noun while lecture is a noun.

Word	Noun	Adjective	Verb	Adverb
teach	No	No	Yes	No
lecture	Yes	No	Yes	No

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

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

teach (verb)	lecture (verb)
accustom gradually to some action or attitude	censure severely or angrily
impart skills or knowledge to	deliver a lecture or talk