confound

What it means

1. To perplex or puzzle.

   And the brother of Jared being a large and mighty man, and a man highly favored of the Lord, Jared, his brother, said unto him: Cry unto the Lord, that he will not confound us that we may not understand our words.

   1830, Joseph Smith, Jr., Book of Mormon: Ether, i, 34

   1 more example

   The fightback when it came was in the [Roger] Federer fashion: unfussy, filled with classy strokes from the back with perfectly timed interventions at the net that confounded his opponent. The third set passed in a bit of a blur, the fourth, which led to the second tie-break, was the most dramatic of the match.

   2012 June 29, Kevin Mitchell, “Roger Federer back from Wimbledon 2012 brink to beat Julien Benneteau”, in The Guardian, archived from the original on 15 Nov 2016

   Synonyms: puzzle, vex

2. To stun or amaze.
3. To fail to see the difference; to mix up; to confuse right and wrong.

   1 more example

   They vvho leſſe ſeriouſly conſider the force of vvords, doe ſometimes confound Lavv vvith Counſell, ſometimes vvith Covenant, ſometimes vvith Right. They confound Lavv vvith Counſel, vvho think, that it is the duty of Monarchs not onely to give ear to their Counſellours, but alſo to obey them, as though it vvere in vaine to take Counſell, unleſſe it vvere alſo follovved.

   1651, Tho[mas] Hobbes, “[Dominion.] Chapter XIV. Of Lawes and Trespasses.”, in Philosophicall Rudiments Concerning Government and Society. […], London: […] J[ohn] G[rismond] for R[ichard] Royston, […], →OCLC, page 210

   Synonyms: confuse, mix up, addle, baffle, vex, lose, embroil, stick

In a sentence

And the brother of Jared being a large and mighty man, and a man highly favored of the Lord, Jared, his brother, said unto him: Cry unto the Lord, that he will not confound us that we may not understand our words.

1830, Joseph Smith, Jr., Book of Mormon: Ether, i, 34

Where it comes from

1. Latincōnfundō“to mingle, mix together”
2. Old Frenchconfondre
3. Anglo-Normancunfundre
4. Middle Englishconfounden“destroy, ruin, perplex”
5. Englishconfound

From Middle English confounden (“destroy, ruin, perplex”), from Anglo-Norman cunfundre and Old French confondre, from Latin cōnfundō (“to mingle, mix together”). Related to found (“to melt (metals in a foundry)”) (but not to found (“to start”), nor to find) and to fusion.