The pirate song “Fifteen Men on a Dead Man’s Chest” from Treasure Island contains the expression yo-ho-ho.
Fifteen men on the dead man’s chest—
Yo-ho-ho, and a bottle of rum!
Drink and the devil had done for the rest—
Yo-ho-ho, and a bottle of rum!
Does this signify laughter, a piratical variation of ho-ho-ho? It doesn’t seem like an amusing little ditty but then pirates probably would have a dark sense of humour. Or is it simply a more piratey song filler than na-na-na?