to stop, cease: to bring or come to a halt, leaving off an action or letting something run out
At its heart this word means to come to a stop. Most often a person is the one who stops: they leave off speaking, praying, teaching, or beating someone (Luke 5:4; Acts 21:32). It can also describe a thing running out of force on its own, as when the wind and waves die down and the lake goes still (Luke 8:24), or when an uproar settles (Acts 20:1).
A striking group of uses turns the idea around by negating it. To say the apostles "did not cease" teaching, or that Paul "does not cease" to pray and give thanks, is a vivid way of saying they kept at it without letup (Acts 5:42; Colossians 1:9; Ephesians 1:16). The point of these lines is steady persistence, not that anything stopped.
Once the word is used of a person making something else stop: the believer is told to keep the tongue from evil (1 Peter 3:10), holding it back rather than letting it run loose. And in one famous line Paul says tongues "will cease" (1 Corinthians 13:8), a plain statement that they will come to an end, set beside a different verb, καταργέω, used of prophecy and knowledge being done away.