adj.说教的，好为人师的,
Merriam-Webster Online Dictionary
preachy (adjective)marked by obvious moralizing - didactic put off by the speaker's preachy tone
Merriam-Webster Online Thesaurus
preachy (adjective)marked by or given to preaching moral values
SYNONYMS:
didactic, homiletic ( homiletical), moralistic, moralizing, preachy, sententiousRELATED WORDS:
dogmatic ( dogmatical), prescriptive; admonishing, admonitory, cautionary; advisory, enlightening, instructive; holier-than-thou, self-righteous