extirp > extirpate privily > secretly; hence: away from view
7 Down in a darksome lowly place far in, 8 Where he meant his corrosives to apply,
corrosives > remedies, caustic drugs
9 And with strait diet tame his stubborn malady.
strait > strict diet > {Way of living or thinking} stubborn > unyielding, intractable (cf. 108.25:4)
110.26
In ashes and sackcloth he did array
2 His daintie corse, proud humors to abate,
And dieted with fasting euery day,
4 The swelling of his wounds to mitigate,
And made him pray both earely and eke late:
6 And euer as superfluous flesh did rot
Amendment readie still at hand did wayt,
8 To pluck it out with pincers firie whot,
That soone in him was left no one corrupted iot.
1 In ashes and sackcloth he did array 2 His dainty corse, proud humours to abate,
dainty corse > handsome body proud > proud, arrogant; lascivious; swollen, superfluous humours > {Habits of mind; mental qualities, inclinations; also: the four cardinal "humours" of the body whose proportions, in medieval physiology, were believed to determine one's mental and physical qualities} abate > destroy; abate
3 And dieted with fasting every day, 4 The swelling of his wounds to mitigate, 5 And made him pray both early and eke late: