Brown Driver Briggs

 1. to pasture, tend, graze, feed
  1) (Qal)
1a1. to tend, pasture
1a  1) to shepherd
1a  2) of ruler, teacher (fig)
1a  3) of people as flock (fig)
1a  4) shepherd, herdsman (subst)
1a2. to feed, graze
1a  1) of cows, sheep etc (literal)
1a  2) of idolater, Israel as flock (fig)
  2) (Hiphil) shepherd, shepherdess
2. to associate with, be a friend of (meaning probable)
  1) (Qal) to associate with
  2) (Hithpael) to be companions
3. (Piel) to be a special friend