1. [n]  an ancient upright stone slab bearing markings
2. [n]  the usually cylindrical central vascular portion of the axis of a vascular plant

STELE is a 5 letter word that starts with S.

1. \Ste"le\, n. [NL.]
   Same as {Stela}.
   
         One of these steles, containing the Greek version of
         the ordinance, has recently been discovered. --I.
                                                  Taylor (The
                                                  Alphabet).
   
   

2. \Stele\, n. [See {Stale} a handle.]
   A stale, or handle; a stalk. [Obs.] --Chaucer. Holland.