1. (

• intervene ,
• step_in ,
• interfere ,
• interpose

) get involved, so as to alter or hinder an action, or through force or threat of force; "Why did the U.S. not intervene earlier in WW II?" ;

2. (

• intervene

) be placed or located between other things or extend between spaces and events; "This interludes intervenes between the two movements"; "Eight days intervened" ;

3. (

• intervene

) occur between other event or between certain points of time; "the war intervened between the birth of her two children" ;