Worship

Has worship somehow come to mean singing?

The most common word translated worship in the Old Testament (shachah, 172x) means to bow down, prostrate oneself, before a monarch or superior.

The most common word for worship in the New Testament (proskuneo, 60x) means to do reverence to, I go down on my knees to, to kiss the ground when prostrating before a superior.

Praise

Has praise somehow come to mean thanksgiving?

Praise means to express admiration or approval of the achievements or characteristics of a person or thing (Cambridge). A synonym would be to compliment someone.

Praise is like thanksgiving, but it’s about God, not about what we get from him.

Here’s how David praised God:

Praise be to you, Lord, the God of our father Israel, from everlasting to everlasting. Yours, Lord, is the greatness and the power and the glory and the majesty and the splendor, for everything in heaven and earth is yours. Yours, Lord, is the kingdom; you are exalted as head over all. Wealth and honor come from you; you are the ruler of all things. In your hands are strength and power to exalt and give strength to all. Now, our God, we give you thanks, and praise your glorious name. – 1 Chronicles 29:10-13

Shout for joy to God, all the earth! Sing the glory of his name; make his praise glorious. Say to God, “How awesome are your deeds! So great is your power that your enemies cringe before you. All the earth bows down to you; they sing praise to you, they sing the praises of your name.”  Come and see what God has done, his awesome deeds for mankind! He turned the sea into dry land,  they passed through the waters on foot—  come, let us rejoice in him. He rules forever by his power, his eyes watch the nations— let not the rebellious rise up against him. – Psalm 66:1-7

Sing to God, sing in praise of his name, extol him who rides on the clouds; rejoice before him—his name is the Lord. A father to the fatherless, a defender of widows, is God in his holy dwelling. God sets the lonely in families, he leads out the prisoners with singing; but the rebellious live in a sun-scorched land. When you, God, went out before your people, when you marched through the wilderness, the earth shook, the heavens poured down rain, before God, the One of Sinai, before God, the God of Israel. You gave abundant showers, O God; you refreshed your weary inheritance. Your people settled in it, and from your bounty, God, you provided for the poor. – Psalm 68:4-10