Abarim Publications' online Biblical Hebrew Dictionary
The verb בלע (bala') means to swallow up or down - people their food (Isaiah 28:4), snakes their prey (Exodus 7:12), the earth rebels (Numbers 16:30). This verb is often used to mean ruin and destruction (Lamentations 2:2).
In Psalm 55:10 this verb (or as HAW Theological Wordbook of the Old Testament proposes, a whole other, derived verb) is used to mean confuse, much like the verb בלל (balal), confuse, mix, as used in Genesis 11:7.
This root's only derivative is the masculine noun בלע (bela), meaning a swallowing (= a destruction; Psalm 52:6) or a thing swallowed (Jeremiah 51:44).