brag

The story

1. Old Norse · derived frombraka“to creak”
2. Old Norse · derived frombragr“best; foremost; poetry”
3. Middle English · inherited frombraggen“to make a loud noise; to speak boastfully”
4. English todaybrag

From Middle English braggen (“to make a loud noise; to speak boastfully”) of uncertain origin. Possibly related to the Middle English adjective brag (“prideful; spirited”), which is probably of Celtic origin; or from Old Norse bragr (“best; foremost; poetry”); or through Old English from Old Norse braka (“to creak”).