As an adverb keenly
is in a keen manner.
As an adjective keener is
(keen).
As a noun keener is
(dated) one who keens at a funeral.
keener
English
Adjective
(head)
(keen)
Noun
(
en noun)
(dated) One who keens at a funeral.
(informal, UK, Canada) Someone who is excessively keen or eager, possibly making others look bad; a brown-noser.