" entered (into or upon) "

1: to take the first step in (a process or course of action);

  * e.g., " ... a series of counseling sessions intended to help young couples about to enter into the trials and tribulations of marriage "

•  Synonyms : 

•  began,

•  commenced,

•  embarked (on or upon),

•  fell (to),

•  got off,

•  kicked off,

•  launched,

•  led off,

•  opened,

•  started,

•  struck (into)

•  Antonyms : 

•  concluded,

•  ended,

•  finished,

•  terminated