/ik spul"sheuhn/ , n.
1. the act of driving out or expelling: expulsion of air.
2. the state of being expelled: The prisoner's expulsion from society embittered him.
[ 1350-1400; ME expulsion- (s. of expulsio ), equiv. to expuls ( us ) driven out (ptp. of expellere to EXPEL) + -ion- -ION ]