[1] : WordNet (r) 2.0

rein in
     v 1: stop or slow up one's horse or oneself by or as if by
          pulling the reins; "they reined in in front of the post
          office" syn: rein
     2: control and direct with or as if by reins; "rein a horse"
        syn: harness, draw rein, rein
     3: stop or check by or as if by a pull at the reins; "he reined
        in his horses in front of the post office" syn: rein
see also:
rein harness draw rein 

Rein >> R Words
Rein, definition of term: Rein
rein_pag1.html

Rein In >> R Words
Rein In, definition of term: Rein In
rein+in_pag1.html