up to the hilt

to the hilt

As much or to the greatest degree possible; completely or utterly. They've had to borrow to the hilt to get the company off the ground. We're ready to defend our client to the hilt in court.
See also: hilt
Farlex Dictionary of Idioms.

to the hilt

Also, up to the hilt. Completely, to the maximum degree, as in The house was mortgaged up to the hilt. This idiom alludes to the handle ( hilt) of a sword, the only portion that remains out when the weapon is plunged all the way in. The figurative use of the term was first recorded in 1687.
See also: hilt
The American Heritage® Dictionary of Idioms by Christine Ammer.

to the hilt

or

up to the hilt

COMMON
1. If you do something to the hilt or up to the hilt, you do it to the greatest possible extent. He'll be a good candidate. We'll back him up to the hilt. If Fred raises this issue tomorrow, I'll defend my actions to the hilt.
2. If you borrow money to the hilt or up to the hilt, you borrow as much as possible. The company had borrowed to the hilt and still needed more capital. His father's estates were mortgaged up to the hilt. Note: The hilt of a sword or knife is its handle. The image here is of a knife or sword being pushed in all the way to the handle.
See also: hilt
Collins COBUILD Idioms Dictionary, 3rd ed.

(up) to the hilt

completely.
The image is that of plunging the blade of a knife deeply into something, so that only the hilt is visible.
See also: hilt
Farlex Partner Idioms Dictionary

(up) to the ˈhilt

(support, etc. somebody) completely: I will support you to the hilt on this.
This expression refers to the full length of a sword, up to its handle (= the hilt).
See also: hilt
Farlex Partner Idioms Dictionary

to the hilt

To the limit; completely: played the role to the hilt.
See also: hilt
American Heritage® Dictionary of the English Language, Fifth Edition.

up to the hilt

To the utmost. The hilt is the handle of a dagger or sword; when the weapon is plunged all the way into something, only the hilt stays out. The term, also put as to the hilt, was transferred to other kinds of extreme by the seventeenth century. “The estate was mortgaged up to the hilt,” wrote James Payn (Thicker than Water, 1883).
See also: hilt, up
The Dictionary of Clichés by Christine Ammer
See also:
  • hilt
  • to the hilt
  • lay (something) to waste
  • lay to waste
  • made from whole cloth
  • made out of whole cloth
  • out of whole cloth
  • cut from whole cloth
  • cut out of whole cloth
  • chocolate
References in periodicals archive
But a second pathologist, Dr Peter Jerreat, said he had not seen any evidence that the knife had gone up to the hilt.