Answer: ab

AnswerCrossword Clue
abAirman Basic
abantibody
ababdominal muscles
abairborne
aban abdominal muscle
abthe 11th month of the civil year or the 5th month of the ecclesiastical year in the Jewish calendar see month table
abmajor blood group usually enabling a person whose blood is of this type to donate blood to persons of type AB and to receive blood from persons of type O, A, B, or AB
ab(formerly) astatine. Symbol: Ab
abable seaman
abantiballistic; antiballistic missile
abAlberta, Canada (approved for postal use)