He was the very 'definition' of a gentleman. [=he was a perfect gentleman]
The picture lacks 'definition'. [=the picture is not sharp/clear]
A glider is 'by definition' an aircraft with no engine.
(..) and it's over now. Not as far as I'm concerned. What's it gonna be, city boy? I can put you in jail... ...or you can go home. And that's your definition of justice? Many different forms of justice, Chris. See, you've got man's, God's... ...and even the devil's. Certain forms you just can't control. (..)2006 Silent Hill