morphology
mor.phol.o.gy \-je-\ n [G morphologie, fr. morph- + logie -logy] 1a: a branch of biology that deals with the form and structure of animals a nd plants 1b: the features comprised in the form and structure of an organism or any of its parts 2a: a study and description of word formation in a language including infle ction, derivation, and compounding 2b: the system of word-forming elements and processes in a language 3a: a study of structure or form 3b: STRUCTURE, FORM 4: the external structure of rocks in relation to the development of erosio nal forms or topographic features
Webster's English Dictionary