(''formally'') An arrow in a category; (''less formally'') an abstraction that generalises a map from one mathematical object to another and is structure-preserving in a way that depends on the branch of mathematics from which it arises. Category:en:Functions
1982, Israel Program for Scientific Translations (translator), Lev J. Leifman (editor of translation), N. N. Čencov, ''Statistical Decision Rules and Optimal Inference'', (w), Translations of Mathematical Monographs, Volume 53, page 50,
- 1° ''The composition of two morphisms is defined if and only if the final object of the first morphism is the initial object of the second. This composition is also a morphism, whose initial object is the initial object of the first morphism and whose final object is the final object of the second.''
1992, Terrance Brown (translator), Gil Henriques, ''Chapter 13: Morphisms and Transformations in the Construction of Invariants'', Terrance Brown (translator), Jean Piaget, Gil Henriques, Edgar Ascher (editors), ''Morphisms and Categories: Comparing and Transforming'', page 198,
- In certain extreme cases in mathematics, the synthesis of morphisms and of transformations is so intimate that one can speak of a veritable fusion.(..)Essentially, categories are sets of morphisms organized into operatory systems.
2007 November, Steven Dale Cutkosky, ''Toroidalization of Dominant Morphisms of 3-Folds'', Memoirs of the (w), Volume 190, Number 890, page 3,
- The proof of toroidalization of morphisms of 3-folds to surfaces in C3 breaks up into two parts: a reduction to prepared morphisms and then a proof of toroidalization of prepared morphisms from ''n''-folds to surfaces in CK.
(quote-book) The colour morphism of males is proved to be irreversible after its expression at an early stage of ontogeny.