“Morphology: The study of the grammatical structure of words and the categories realized by them. Thus, a morphological analysis will divide girls into girl and –s; singer into sing and –er, which marks it as a noun referring to an agent.
A category is ‘morphological’ if it is realized within words. This morphological case is case as realized by different elements within nouns or words of other classes as opposed to an abstract case which might be realized differently or not at all. A morphological causative is a causative form of a verb as opposed to a causative construction, and so on.”
Excerpted from: Matthews, P.H., ed. The Oxford Concise Dictionary of Linguistics. New York: Oxford University Press, 2014.