SHEAF is a 5 letter word that starts with S.

1. \Sheaf\, n. (Mech.)
   A sheave. [R.]
   
   

2. \Sheaf\, n.; pl. {Sheaves}. [OE. sheef, shef, schef, AS.
   sce['a]f; akin to D. schoof, OHG. scoub, G. schaub, Icel.
   skauf a fox's brush, and E. shove. See {Shove}.]
   1. A quantity of the stalks and ears of wheat, rye, or other
      grain, bound together; a bundle of grain or straw.
   
            The reaper fills his greedy hands, And binds the
            golden sheaves in brittle bands.      --Dryden.
   
   2. Any collection of things bound together; a bundle;
      specifically, a bundle of arrows sufficient to fill a
      quiver, or the allowance of each archer, -- usually
      twenty-four.
   
            The sheaf of arrows shook and rattled in the case.
                                                  --Dryden.
   
   

3. \Sheaf\, v. t.
   To gather and bind into a sheaf; to make into sheaves; as, to
   sheaf wheat.
   
   

4. \Sheaf\, v. i.
   To collect and bind cut grain, or the like; to make sheaves.
   
         They that reap must sheaf and bind.      --Shak.