Definition of "round in"

round in

verb
third-person singular simple present rounds in, present participle rounding in, simple past and past participle rounded in
1. (nautical) To haul up; usually, to haul the slack of (a rope) through its leading block, or to haul up (a tackle which hangs loose) by its fall.
  Quotations
  Moncrieff rounded in the slack of the rope and landed the captain most beautifully.
  1891, William Gordon Stables, Our Home in the Silver West
2. (US, dated) To round up (cattle) by riding around them.