3 And all the sleights unbosomed in his heart:

sleights > ruses, stratagems

4 He sighed, he sobbed, he swooned, he pardie died,

pardie > assuredly, verily (an oath)

5 And cast himself on ground her fast beside;

fast > closely

6 Tho when again he him bethought to live,

Tho > Then him bethought > contrived; resolved

7 He wept, and wailed, and false laments belied,

belied > misrepresented; lied about (tautological, and thus intensive)