Grumble

gruñido

(the sound made by a hungry stomach)

refunfuñadura

(a high thundering, rumbling or growling sound)

gruñir

(to make a low growling or rumbling stomach noise)

lamentarse

(to murmur or mutter with discontent)

refunfuñar

(to murmur or mutter with discontent)

rezongar

(to murmur or mutter with discontent)

rezonglar

(to murmur or mutter with discontent)

rosigar

(to murmur or mutter with discontent)

varraquear

(to murmur or mutter with discontent)

verraquear

(to murmur or mutter with discontent)