NEC rules sometimes refer to "the yoke".
For example: 1999 NEC § 210-4(b):
Dwelling Units. In dwelling units, a multiwire branch circuit supplying more than one device or equipment on the same yoke shall be provided with a means to disconnect simultaneously all ungrounded conductors at the panelboard where the branch circuit originated.
What is meant by the term 'Yoke' as used in the NEC?