1. beshrew: to invoke evil upon, to wish (one) all that is bad, to invoke a curse on; to curse, objurgate, or blame greatly, as the cause of misfortune. Obsolete.

2. it: mistress' heart.

5. thy cruel eye: the cruel eye of the disdainful mistress was a traditional motif.

6. my next self: my dearest friend.   harder: more securely.   engross'd: monopolized.

8. cross'd: afflicted; tried.

9. steel bosom's ward: the prison cell of your hard heart.

10. bail: liberate by suffering in its place.

11. keeps me: is my jailor; i.e., also perhaps the one who loves me best.   his guard: my friend's guardhouse.

12. rigor: an act or instance of harsh inflexibility, severity, or cruelty; a severe or injurious action or proceeding; i.e., torture.

13. pent: imprisoned.

14. perforce: forcibly; necessarily.