Answer: sis

AnswerCrossword Clue
SISPro votes, in Panama
SISBro's twin
SISSally, to Charlie Brown
SISFamily member, for short
SISEva, to Zsa Zsa
SISWhat Audrey Meadows calls Jayne?
SISMember of the fam
SISShirley, to Warren
SISBro's sibling
SISBro counterpart
SIS"Boom-bah" lead-in
SISSpanish ayes
SISOne Dionne quint to another
SISOne of a fam
SISAuntie, to Mom, maybe
SISKin of bro
SISMalia, to Sasha
SIS"... boom bah!"
SISFamily member, briefly
SISOne of the fam
sisa sister
SISMarie, to Donny
SISBoom preceder, perhaps
SISMagda, to Zsa Zsa
SISSib's nickname
SIS".... Boom Bah" : Heller novel
SISBro's kin
SISCheer starter
SISFamily member
SISFamily nickname
SISLorna, to Liza
SISAuntie, to mom
SIS.... boom bah
SIS.... boom bah (cheer)
SISClose relative
SISLisa, to Bart
SISSee 34A
SISFamily address
SISLindsay, to Gob and Michael
SISSibling nickname