Definify.com
Webster 1913 Edition
Selah
Se′lah
,Noun.
[Heb.
selāh
.] (Script.)
A word of doubtful meaning, occuring frequently in the Psalms; by some, supposed to signify silence or a pause in the musical performance of the song.
Beyond the fact that
Selah
is a musical term, we know absolutely nothing about it. Dr. W. Smith (Bib. Dict.)