eagerness - adj.
1 a full of keen desire, enthusiastic. b (of passions etc.) keen, impatient.
2 keen, impatient, strongly desirous (eager to learn; eager for news).

eager beaver colloq. a very or excessively diligent person.

eagerly adv. eagerness n. [ME f. AF egre, OF aigre keen, ult. f. L acer acris]