Curtail me, and I'm what you use

Puzzle

Curtail me, and I'm what you use
To do my whole, 'tis true,
And which I'm sure few will refuse,
Woe be to them who do!

Hint

Answer

References

• Loyd, Sam [1914]. in Loyd, Sam, Jr.: Sam Loyd's Cyclopedia of 5000 Puzzles Tricks and Conundrums (in English). New York: Lamb Publishing company, page 43.