Psalm 64:9, NIV:

All people will fear; they will proclaim the works of God and ponder what he has done.

The "fear of the Lord" refers to -

Having a deep respect, reverence, and awe for God's power and authority.

Recognizing God's infinite power, wisdom, and authority over all creation.

Being soberly aware of God's divine authority and not trivializing His judgment or wrath.

Reverencing God as one would pay to a king because of His majesty.