Congress 'whacked' the budget by 1.5 billion dollars. = Congress 'whacked' 1.5 billion dollars from the budget.
Their priorities are (all) 'out of whack'. [=they do not understand what things are actually important]
I paid 'top whack' [=('US') 'top dollar'] for these items. [=I paid the highest amount possible]
(..) It's just the rain, Donkey. Oh. Don't worry. Things seem bad because it's dark and rainy and Fiona's father hired a sleazy hitman to whack you. It'll be better in the morning. You'll see... # The sun'll come out... # Tomorrow # Bet your bottom...? (..)2004 Shrek 2