Define what remnant means to you.Please try and keep it simple,but don't describe remnant with just a word or two.
Paul describes remnant:
Romans 11:4-5 (NASB):
But whatis the divine response to him? “I have kept for Myself seven thousand men who have not bowed the knee to Baal.” In the same way then, there has also come to be at the present time a remnant according to God’s gracious choice.
Paul is paraphrasing 1 Kings 19:18-
Yet I will leave 7,000 in Israel, all the knees that have not bowed to Baal and every mouth that has not kissed him.”
Paul is referring to Elijah, during OT times. Elijah was denouncing Israel to God who replies that they're not all bad, that there are some--more than you might think--who have remained faithful to Him. Paul calls them the Remnant (though the word is not used in the above OT chapter).
The remnant in this case is all who have remained faithful to God and were not worshiping the false deity Baal. The remnant are those who kept the first commandment (Ex 20:3):
“You shall have no other gods before Me.
We might feel safe in that we are not worshiping idols and false gods as the ancient Hebrews did. But we are not safe at all. Many in our culture do idolize things. For some, they love money more than they love God. This too is idolatry.
You can also substitute sex, power, security, fame, control, and probably a dozen other things for "money" that some people prioritize ahead of God. That is the modern idolatry and we are no better than the ancient Hebrews.
...but there is a remnant, and they are more numerous than you might think.