Thou lovest all devouring words - All words that tend to devour or "swallow up" reputation and happiness. Luther, "Thou speakest gladly all things (anything) that will serve to destruction." Anything, everything, that will serve to ruin people. The word rendered "devouring" - בלע bela‛ - occurs only here and in Jeremiah 51:44, though the verb from which it is derived occurs frequently: Isaiah 28:4; Exodus 7:12; Jonah 2:1 Jonah 1:17; Genesis 41:7, Genesis 41:24, et al. The verb means to swallow; and then, to consume or destroy.
O thou deceitful tongue - Margin, "and the deceitful tongue." The sense is best expressed in the text. It is an address to the tongue as loving deceit or fraud.

Thou lovest all devouring words,.... Or "words of swallowing up" (y); such as lies, calumnies, and detractions are, which devour the characters and reputations of men, and are the cause sometimes of their utter ruin and destruction; of the devouring and blasphemous words of antichrist see Revelation 13:5;
O thou deceitful tongue; See Gill on Psalm 52:2.
(y) "verba absorptionis", Vatablus, Gejerus, Schmidt.

all-devouring--literally, "swallowing," which utterly destroy (compare Psalm 21:9; Psalm 35:25).