A word akin to froward that we are probably all more familiar with is the word perverse. Perverse is defined as, "turned aside; hence, distorted from the right."
Let's compare the following verses regarding a perverse heart.
He that walketh in his uprightness feareth the Lord: but he that is perverse in his ways despiseth him. (Proverbs 14:2)
A man shall be commended according to his wisdom: but he that is of a perverse heart shall be despised. (Proverbs 12:8)
These two verses beautifully illustrate the truth of Galatians 6:7. That is, you reap what you sow. A perverse heart is one that despises God instead of fearing Him. In turn, God despises the man with the perverse heart, as opposed to commending Him.
And I promise you want God's commendation. You don't want Him to despise you. I can think of two men in the Bible who out of a perverse heart despised God or His representative, and were thus despised by God.
One is Nabal (you can read about his fate in 1 Samuel 25), and the other is Haman the Agagite (Esther 7-9). The Bible says of both men that God returned their wickedness on their own heads…which doesn't sound pleasant or enjoyable (but does sound like a good Bible study! check these references out: 1 Samuel 25:39; 1 Kings 8:32; 2 Chronicles 6:23; Nehemiah 4:4; Esther 9:25; Psalm 7:16; Proverbs 25:22; Ezekiel 7:10; Ezekiel 16:43; Ezekiel 17:19; Joel 3:4, 7; Obadiah 1:15; Romans 12:19-21).
The man with a perverse heart is met with swift destruction (Proverbs 28:18). Proverbs says it would be much better for that man to be poor (Proverbs 19:1; 23:33; 28:6) indicating that many "turn aside" from God to seek after wealth. Their end is destruction (1 Timothy 6:9-11).