sound (v.) 2
find out, ascertain, sound out
1H6 I.ii.63 [Charles to Reignier, of their way of testing Pucelle] By this means shall we sound what skill she hath
2H4 IV.ii.51 [Prince John to Hastings] You are too shallow ... / To sound the bottom of the after-times [i.e. plumb the depths]
Cym IV.ii.204 [Belarius to Arviragus and Guiderius] O melancholy, / Who ever yet could sound thy bottom [i.e. plumb thy depths]
MW II.i.219 [Ford alone] I have a disguise to sound Falstaff
R2 I.i.8 [King Richard to John of Gaunt, of Bolingbroke] hast thou sounded him