Slack (Verb), Slackness - Vine's Expository Dictionary of New Testament Words
Slack (Verb), Slackness
[ A-1,Verb,G1019, braduno ]used intransitively signifies to be slow, to tarry" (bradus, "slow"), said negatively of God, 2 Peter 3:9, "is (not) slack;" in 1 Timothy 3:15, translated "(if) I tarry." See TARRY. In the Sept., Genesis 43:10; Deuteronomy 7:10; Isaiah 46:13.
[ B-1,Noun,G1022, bradutes ]
"slowness" (akin to A), is rendered "slackness" in 2 Peter 3:9.