Mat 15:10 Hear, and understand :
Listen, and you put [it] together!
The word translated as "understand" means something more than that and it is chosen for a reason.
Christ uses a couple of different Greek word that can be translated as "hear." This particular one means not just hearing with the ear, but listening so you can understand. It can also be translated as "understand" though the KJV never does that.
The word translated as "understand" means "to bring together." It means "understand" in the same sense that we say "put it together" to mean "understand." This word is always translated as "understand" in the KJV translation. A number of other Greek words begin with the same prefix, and all mean some form for bringing things together, for calling a meeting to gathering a crop.
This tells us that Christ's idea of "understanding" was more like putting together pieces of a puzzle, not a passive process.
Ἀκούετε (verb 2nd pl pres imperat act) "Hear" is from akouo, which means "hear of", "hear tell of", "what one actually hears", "know by hearsay", "listen to", "give ear to", "hear and understand," and "understand."
καὶ "And" is from kai, which is the conjunction joining phrases and clauses, "and," or "but." After words implying sameness, "as" (the same opinion as you). Used in series, joins positive with negative "Not only...but also." Also used to give emphasis, "even", "also," and "just."
συνίετε: (verb 2nd pl pres ind/imperat act) "Understand" is from syniemi which means "to bring together" or "to set together." It is also a metaphor for "perceive", "hear," and "understand" as we would say that we "put it all together" when figuring something out.