Goggystes (γογγυστής) is the agent noun of goggyzo — a grumbler or chronic murmurer. It appears only once in the New Testament (Jude 16), where Jude characterizes the false teachers invading the church as 'grumblers and fault-finders [goggystai].' This is one of the sharpest condemnations in the New Testament epistles.
Jude's use of goggystes links the false teachers to the most rebellious figures in Israel's history. The wilderness generation's murmuring against God led to judgment (Numbers 11, 14, 16–17). Jude sees the same spirit in the antinomian teachers of his day — people who grumble against spiritual authority, follow their own desires, and flatter others for personal gain (Jude 16). Grumbling, when it becomes a character trait, is a theological problem: it reveals a heart that has not surrendered to God's goodness. The antidote is not suppression but transformation — the grateful heart cannot chronically grumble.