NT.filter - nkjv grumble:

nkjv@James:5:9 @ Do not grumble against one another, brethren, lest you be condemned. Behold, the Judge is standing at the door!

nkjv@Jude:1:16 @ These are grumblers, complainers, walking according to their own lusts; and they mouth great swelling words, flattering people to gain advantage.