What is All-out?
1.
Giving as much effort as possible; not holding back.
'All' refers to everything, and 'out' is an intensifier. So 'all-out' means 'everything and more'.
1) Karen went all-out in the race, and won a gold medal.
2) Captain Barne's final act was to order an all-out assault on the fortress.
2.
to go balls deep, or to give it your all. to try really hard and give a situation 100% of your attention
"man, pedro really goes all-out"
See
3.
not hold anything back, sparing nothing
Both sides went all-out when the game started.
