{"era":"current","word":"grumble","meaning":"to complain in a low, muttering, or dissatisfied way","children":[{"era":"1300s","word":"Middle English grumblen / grumelen","meaning":"to mutter, murmur, or complain","children":[{"era":"medieval","word":"expressive base grum-","meaning":"rough, rumbling sound","children":[],"language":"Germanic / imitative"}],"language":"Middle English"}],"language":"Modern English"}