Both Uses of
lament
in
Henry IV, Part 2
-  Fair daughter, you do draw my spirits from me
 With new lamenting ancient oversights.Scene 2.3 *lamenting = expressing grief or regret
- Why then, lament therefore.†
Scene 5.3lament = express grief or regret
Definitions:
- 
(1)
(lament) to express grief or regret
- 
(2)
(meaning too rare to warrant focus) meaning too rare to warrant focus:
 Although lament typically refers to a feeling or simple vocal expression, it can refer to a vocal expression as complex as a sad song or poem. It can even refer to sad, but non-vocal music -- as when Tennessee Williams references background music in A Streetcar Named Desire.