Definition:  To sow discord is to create a state of bitterness and enmity among people, things, or ideas that are marked by a lack of agreement and harmony. Sowing discord implies an inherent absence of harmony, thus producing quarreling, factiousness, or antagonism.

Etymology: 

Sow discord originated in the 13th century from the French word discorder and discorden, which meant “differ in will or opinion, disagree, quarrel.” 

It’s directly related to the Latin word discordare, which means “be at variance, differ, quarrel” and from discors (genitive discordis), which means “disagreeing, disagreement.” 

In a Sentence

Lately, people are using fake news, conspiracy theories, and disinformation as a political weapon intended to sow discord in democracy.

I will sow discord between them and her.

Proverbs 6:16-19 – These six things doth the Lord hate: yea, seven are an abomination unto him: A proud look, a lying tongue, and hands that shed innocent blood, An heart that deviseth wicked imaginations, feet that be swift in running to mischief, A false witness that speaketh lies, and he that soweth discord among brethren.

Synonyms 

Create dissension, Stir the pot, Drive a wedge

Antonyms 

Unite, Come to an understanding, Incorporate