Glossary Term Definition
The height of the type body, which in letterpress is the height of the face of the metal block on which each letter is cast; in digital type, the body is the height of its imaginary equivalent.
Definition
The height of the type body — which in letterpress is the height of the face of the metal block on which each letter is cast. In digital type, the body is the height of its imaginary equivalent, an invisible rectangle known as the em square. The body is always somewhat larger than the face of the letter itself.
Source
No access — Robert Bringhurst — p. 322:
The height of the type body — which in letterpress is the height of the face of the metal block on which each letter is cast.