Answer: btwo

AnswerCrossword Clue
BTWOU.S. stealth bomber (usually written with a numeral, but how about a little creative license?)
BTWORiboflavin designation
BTWOUSAF stealth plane
BTWOCall in a bingo hall
BTWOKind of bomber
BTWORiboflavin, familiarly
BTWOVitamin a.k.a. riboflavin
BTWOStealth bomber
BTWOVitamin also known as riboflavin