"pertaining to baths," 1640s, with -al (1) + Latin balneum "bath," from Greek balaneion "warm bath, bathing room," which is of unknown origin. Balneography (1841) is the description of baths and medicinal springs.
ballsy
bally
ballyhoo
balm
balmy
balneal
baloney
balsa
balsam
balsamic
Balt