Kathar is a verb meaning to surround, to encircle, to crown, or to wait upon/petition. The meaning ranges from the physical (surrounding a city in siege) to the metaphorical (being crowned with glory) to the devotional (waiting upon God in prayer). Related to the noun keter (crown), it suggests that encompassing something is like placing a crown upon it.
Psalm 142:7 uses this word: 'the righteous will gather about me [kathar] because of your goodness to me.' Community surrounds the delivered saint. Job 36:2 uses it for the act of waiting upon and serving God. Habakkuk 1:4 speaks of the wicked surrounding the righteous — yet the same encompassing God reverses this: He surrounds His people with favor as a shield (Ps 5:12). The theology is that what surrounds you defines you; when God's presence encircles His people, they are crowned with His protective love.