—used to say that one thing has the same effect or result as something else Their decision to begin bombing was, for all intents and purposes, a declaration of war.

What do by all means mean?

used for politely agreeing with someone, giving permission, or saying 'yes' 'Do you mind if I invite a few friends? ' 'By all means. '

How do you use by all means?

You can say 'by all means' to tell someone that you are very willing to allow them to do something. 'Can I come and have a look at your house?' —'Yes by all means'.