Banjo hitter

From BR Bullpen

Banjo hitter refers to a batter with little power, perhaps echoing the soft plunking sound of a short soft hit leaving the bat. Snooks Dowd is credited with coining the term "banjo hit".

A "Punch & Judy" hitter is a similarly derogatory term. With today's players at every position swinging from their heels it is harder for light hitters to hold their jobs even if they perform well at other aspects of the game.