Fusional language

Fusional languages or inflected languages are a type of synthetic language, distinguished from agglutinative languages by their tendency to use single inflectional morphemes to denote multiple grammatical, syntactic, or semantic features.

For example, the Spanish verb comer ("to eat") has the first-person singular preterite tense form comí ("I ate"); the single suffix -í represents both the features of first-person singular agreement and preterite tense, instead of having a separate affix for each feature.

Another illustration of fusionality is the Latin word bonus ("good"). The ending -us denotes masculine gender, nominative case, and singular number. Changing any one of these features requires replacing the suffix -us with a different one. In the form bonum, the ending -um denotes masculine accusative singular, neuter accusative singular, or neuter nominative singular.