Thanks for the spelling lessen. How's your "sproacket" doing. . . ? See you misspelled again! les·son ( P ) Pronunciation Key (lsn) n. Something to be learned: lessons from observing nature. A period of instruction; a class. An assignment or exercise in which something is to be learned. The act or an instance of instructing; teaching. An experience, example, or observation that imparts beneficial new knowledge or wisdom. The knowledge or wisdom so acquired. A rebuke or reprimand. often Lesson A reading from the Bible or other sacred text as part of a religious service. less·en ( P ) Pronunciation Key (lsn) v. less·ened, less·en·ing, less·ens v. tr. To make less; reduce. Archaic. To make little of; belittle. Mine was a typo, yours was a lack of knowledge.