Explanation: the denotation of a word is its literal meaning, the definition that we can find in a dictionary, a word can have several denotations (or definitions). The definition of the word "ungainly" is lacking in smoothness or dexterity, awkward and without grace. And the denotation of the word "fowl" is a domesticated bird kept for its eggs or flesh. So when the speaker says that the raven is an "ungainly fowl" he means that it is a clumsy bird.
