deficiency
For purposes of this title in the case of income, estate, and gift taxes imposed by subtitles A and B and excise taxes imposed by chapters 41 , 42 , 43 , and 44 the term “deficiency” means the amount by which the tax imposed by subtitle A or B, or chapter 41, 42, 43, or 44 exceeds the excess of—
Source
26 USC § 6211(a)
Scoping language
None identified, default scope is assumed to be the parent (subchapter B) of this section.