Sandi,
Not quite sure which are the terms you want out of this verse. I presume 'trimmed' would have the same meaning as in any shooting, 'adjusted aim', 'kist' as in his arrow gave a glancing touch as in snooker/billiards/pool, but with the extra loose sexual connotation.
And 'wist' is just 17thc for 'perceived/knew/was aware of'. Don't think there's anything here specific to archery.