A lot vs. Alot: 9 Grammatical Pitfalls
1660s, from Middle English grollen "to rumble, growl" (early 15c.), from Old French grouler "to rumble," said to be from Frankish; probably ultimately of imitative origin. Related: Growled; growling. The noun is 1727, from the verb.
To complain; mutter angrily (1707+)