1. 4 The fault of the ass must not be laid upon the packsaddle. 

2. As the day got warmer, my sweaty legs would sting as they rubbed against the lumps of rock salt in the packsaddle.

3. Bastard "illegitimate child," early 13c., from Old French Bastard "acknowledged child of a nobleman by a woman other than his wife" (11c., Modern French bâtard), probably from fils de bast "packsaddle son," meaning a child conceived on an improvised bed (saddles often doubled as beds while traveling), with pejorative ending -art (see -ard)