Definify.com
Webster 1913 Edition
Sermon
Ser′mon
,Noun.
 [OE. 
sermoun
, sermun
, F. sermon
, fr. L. sermo
, -onis
, a speaking, discourse, probably fr. serer
, sertum
, to join, connect; hence, a connected speech. See Series
.] 1. 
A discourse or address; a talk; a writing; 
as, the 
. sermons 
of Chaucer[Obs.] 
Chaucer.
 2. 
Specifically, a discourse delivered in public, usually by a clergyman, for the purpose of religious instruction and grounded on some text or passage of Scripture. 
This our life exempt from public haunts
Finds tongues in trees, books in the running brooks,
Finds tongues in trees, books in the running brooks,
Sermons 
in stones and good in everything. Shakespeare
His preaching much, but more his practice, wrought,
A living
A living
sermon 
of the truths he taught. Dryden.
3. 
Hence, a serious address; a lecture on one’s conduct or duty; an exhortation or reproof; a homily; – often in a depreciatory sense. 
 Ser′mon
,Verb.
 I.
 [Cf. OF. 
sermoner
, F. sermonner 
to lecture one.] To speak; to discourse; to compose or deliver a sermon. 
[Obs.] 
Holinshed.
 What needeth it to 
 sermon 
of it more? Chaucer.
Ser′mon
,Verb.
 T.
 1. 
To discourse to or of, as in a sermon. 
[Obs.] 
Spenser.
 2. 
To tutor; to lecture. 
[Poetic] 
Shak.
 Webster 1828 Edition
Sermon
SER'MON
,Noun.
             1. A discourse delivered in public by a licensed clergymen for the purpose of religious instruction, and usually grounded on some text or passage of Scripture. Sermons are extemporary addresses or written discourses.
                   His preaching much, but more his practice wrought,
                   A living sermon of the truths he taught. Dryden.
           2. A printed discourse.
SER'MON
,Verb.
 T.
             1. To discourse as in a sermon. [Little used.]