Masturbating woman. The term refers to the traditional Russian string instrument, which requires a specific finger technique (hence the alternative slang meaning).
Балалайка-онанистка там… сбить не хочу… пусть дрочит…
The balalaika-masturbator there… I don’t want to disturb her… let her jerk off…
(Hrach_Techie @ armkb.com, 02/2005)
