it could be blunt
Another word for kindly beginning with 'b' is benevolent.
Botany
backbonebackgroundballparkbaseballbaseboardbasketballbathhousebathtubbathwaterbirdhousebirthdaybirthmarkbirthrightblackbirdblackboardblackmailbloodbathbookmarkbookshelfbluebellbluebirdblueprintboyhoodbrainwavebreadwinnerbreakwaterbrownstonebutterball
Bank on it!
bananabacteriabasilicaballerinabelugabandannabarracudabolognabulimia
Binge
ballistic
bicarbonate
bancs
biotic
Bewitch
Bash