A sailor who bites or gnaws at things (archaic); or more commonly, a type of rhythmic sailor's song sung on ships to coordinate work.
From 'fore-' (forward/front) + 'bitter' (one who bites), or possibly from 'bite' referring to the biting rhythm. The term evolved from describing someone/something at the front to describing rhythmic work songs.
Forebitter sea shanties were literally the playlist for coordinating labor—rowers and sailors would bite the rhythm together, their bodies moving in unison with the song's tempo to hoist sails and raise anchors efficiently.
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