Glossary Term Definition
A serif that flows through the stem and out the other side, as on the foot of letters like b, d, h, and l in many humanist typefaces; contrasts with reflexive serifs.
Definition
A serif that flows through the stem and out the other side, as on the foot of letters like b, d, h, and l in many humanist typefaces. Transitive serifs contrast with reflexive serifs, which bend back toward the direction from which they came. The distinction between transitive and reflexive serifs is a key element in Bringhurst's typographic classification.
Source
No access — Robert Bringhurst — p. 330:
A serif that flows through the stem and out the other side.