From Longman Dictionary of Contemporary Englishstand by phrasal verb1 NOT DO somethingto not do anything to help someone or prevent something from happening → bystander I’m not going to stand by and see her hurt.2 stand by somethingPROMISE to keep a promise, agreement etc, or to say that something is still true I stand by what I said earlier. He stood by his convictions.3 stand by somebodyFAITHFUL to stay loyal to someone and support them, especially in a difficult situation His wife stood by him during his years in prison.4 READYto be ready to do something if necessary → standby Rescue crews were standing by in case of a breakdown. for Stand by for our Christmas competition.stand by to do something Police stood by to arrest any violent fans. → stand→ See Verb table
Examples from the Corpus
stand by• The crew was ordered to stand by for take-off.• The family stood by, knowing that she might wake up any minute.• The Foreign Minister had a helicopter standing by to whisk him to the northern city of Afula.stand for• John Thorn, who makes red boxes for ministers, is standing by for a rash of orders.• Control said all that was just fine, and to stand by for instructions.• With students threatening to run a Barclays-style boycott against any that participate, stand by for more to pull out.• Engineering is advised to stand by for pictures from the live truck and the helicopter.• But it was really quite useful, since it alerted his audience to stand by for something unexpected.• Stand by for the countdown.• They've found the secret of happiness for all! - Stand by for the labour camps and the mass graves. 