A comparative degree marker is a marker that occurs on the parameter expression and that marks the construction as a comparative construction.
degree marker (CXN) = a free morpheme or affix that expresses the relative degree of the gradable predicative scale applied to the comparee, in comparative and equative constructions. Example: in taller, the suffix -er is a degree marker. In addition to comparative and equative degree markers, some languages have a distinct superlative degree marker, such as -est in English tallest. (Section 17.2.2)