noun
young trainee geisha or kabuki actor
Refers to a child apprentice in traditional entertainment districts, training to become a geisha or kabuki performer. The term is specific to these traditional arts contexts.
彼女はまだ下地っ子だが、踊りがとても上手だ。
She is still a young trainee, but her dancing is very good.
芸者 is a fully trained geisha. 下地っ子 is a child apprentice training to eventually become one.
Compound of 下地 (したじ, 'foundation, groundwork') and っ子 (っこ, diminutive suffix for a child). The term suggests a child who is being prepared or trained from the ground up.