Un·der·work v. t. [imp. & p. p. Underworked or Underwrought p. pr. & vb. n. Underworking.]
 1. To injure by working secretly; to destroy or overthrow by clandestine measure; to undermine.
 But thou from loving England art so far,
 That thou hast underwrought his lawful king.   --Shak.
 2. To expend too little work upon; as, to underwork a painting.
 3. To do like work at a less price than; as, one mason may underwork another.