(up) to the hilt
Something that is done (up) to the hilt is done completely and without any limitation:
The government is already borrowing up to the hilt, so it can't afford to spend any more.

[TahlilGaran] Advanced Learner's Dictionary ▲

to the hilt
(up) to the hilt
1.
if you do something to the hilt, you do it in the strongest and most complete way that you can.
All through the trial, he has backed his wife up to the hilt.

They took the new aircraft and tested it to the hilt.

2.
if you borrow to the hilt, you borrow as much money as you can, often so much that it is difficult to pay it back.
We can't raise any more money - we're mortgaged up to the hilt as it is.

With the government borrowing up to the hilt we can expect tax rises.

as much as possible.
We're already being taxed to the hilt.

Etymology: based on the idea of pushing a sword into something to the hilt (= as far as its handle)

[TahlilGaran] English Idioms Dictionary ▲

to the hilt
to the maximum amount, completely
My friend has been in debt to the hilt since he bought his new car.

[TahlilGaran] English Idioms Dictionary ▲

to the hilt
adv. phr. To the limit; as far as possible; completely.
The other boys on the team told Tom he couldn't quit. They said, "You're in this to the hilt."
The Smith's house is mortgaged up to the hilt.
Compare: HEART AND SOUL, TO THE FULL, UP TO THE --- IN.

[TahlilGaran] English Idioms Dictionary ▲