A verb meaning 'to leave behind,' 'to forsake,' or in passive form 'to remain.' Used in Hebrews 4 for the Sabbath rest that 'remains' for God's people, and Jude 1:6 for angels who 'left' their proper place.
The 'remaining rest' in Hebrews 4 is still available -- every generation faces the same invitation. By contrast, the angels of Jude 1:6 abandoned their God-given station and face eternal chains. The same verb: faithful remaining leads to rest; faithless abandonment leads to judgment.