bathorse means A horse which carries an officer's baggage during a campaign. Lexicurio rates it Sui generis — a strength score of 91 out of 100.
noun
- A horse which carries an officer's baggage during a campaign“1857 Washington Irving, Life Of George Washington Vol IV
About ten o’clock the wagons and bat horses laden with Indian corn were returning, covered by a party of infantry, with Tarleton and his dragoons as a rear-guard.”