Very tender, poop regularly, resulting in tear once? (3-4)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Alternate letters (regularly) of [v] E [r] Y [t] E [n] D [e] R [p] O [o] P . Shakespearean word (“once” = in the past but probably not now) for a tear, as in a drop falling from the eye. These days it normally means liquid medicine applied to the eye.