overfluent
/ɒvərˈfluːʒnt/Definitions
1. adjective
having or showing a greater amount of something than is needed or wanted, especially a language or skill.
“The overfluent use of adjectives in the novel made it difficult to read.”
2. noun
an excess of something, especially a language or skill.
“The overfluent student’s knowledge of the language made it difficult for her peers to engage in conversation.”