noeo

νοεῖτε [8 verses](verb 2nd pl pres ind act) "Perceive" is from noeo, means specifically "perceive by the eyes," "observe," "to perceive with the mind," "apprehend," "think out, "devise," "consider," (of words) "bear a certain sense," and "reflect." -- "Do ye...understand" is from a verb that means "to perceive with the eyes," "to perceive with the mind," and "to observe." We use the word "see" to have the same sense of physical seeing and perceiving with the mind. This is the root word for the key word in Jesus's teaching that gets translated as "repent" but which actually means "change your mind."  There are several words translated as "understand" in the Gospels, but this word might be closest.