· 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?"
Synonym(s): intervene, interfere, interpose
Hypernym(s): interact
· act as a substitute; "She stood in for the soprano who suffered from a cold"
Synonym(s): substitute, deputize, deputise
Hypernym(s): supplant, replace, supersede, supervene_upon