entrain

v. board a train; put aboard a train

Verb
1. board a train
(hypernym) board, get on

n. spirit, liveliness; buoyancy, cheerfulness, high spirits; zest

(v. t.)
To put aboard a railway train; as, to entrain a regiment.
  

(v. t.)
To draw along as a current does; as, water entrained by steam.
  

(v. i.)
To go aboard a railway train; as, the troops entrained at the station.
  

To trap bubbles in water either mechanically through turbulence or chemically through a reaction.