Morphophonology (also morphophonemic, morphonology) is a branch of linguistics which studies:

• The phonological structure of morphemes.
• The combinatory phonic modifications of morphemes which happen when they are combined
• The alternation series which serve a morphological function.

Definition (according to Trubetzkoy): In American linguistics the second and the third point are often called morphophonemics.

Morphonology

Morfofonologia