Superabundant describes something that exists in a very large amount — more than enough, more than normal, sometimes more than anyone can use. It is the adjective that goes with the noun 'superabundance'. If food is abundant, there is plenty; if it is superabundant, there is so much that some will be left over. You can use it before a noun ('superabundant energy', 'superabundant rainfall') or after 'be' ('the fish were superabundant that year'). The word is formal and bookish. In ordinary speech people say 'way too much', 'tons of', or just 'so much'; superabundant belongs to written English — science writing, history, essays, literary description. It works for things you can count and things you cannot, and it is often used about nature: superabundant plant life, superabundant sunshine. It can also describe a quality in a person, usually a warm one — superabundant kindness, superabundant enthusiasm — where the picture is of something pouring out of a person and spilling over onto everyone around.