Hitting and Batter Terms

brushback – A pitch that nearly hits a batter.
caught looking – When a batter is called out on strikes.
chin music — A pitch that is high and inside.
dinger – A home run.
gap –  A ball hit here is a “gapper.”
homer – A home run. Other terms include: blast, dinger, dong, four-bagger, four-base knock, moon shot, tape-measure blast and tater.
in the hole – The batter after the on-deck hitter.
jam – When a hitter gets a pitch near his hands, he is “jammed.” Also when a pitcher gets himself in trouble, he is in a “jam.”
Mendoza line – A batting average of around .200.
moon shot – A very long, high home run.
on the screws– When a batter hits the ball hard. Also “on the button.”
pea – A ball traveling at high speed, either batted or thrown.
ribbie – Another way of saying RBI. Also “ribeye.”
rope – A hard line drive hit by a batter. Also “frozen rope.”
Ruthian – With great power.
seeing-eye single – A soft ground ball that finds its way between infielders for a base hit.
tape-measure blast — An extremely long home run.
tater – A home run.
Texas Leaguer – A bloop hit that drops between an infielder and outfielder.
touch ’em all – Hitting a home run (touching all the bases).
wheelhouse – A hitter’s power zone. Usually a pitch waist-high and over the heart of the plate.
wheels – A ballplayer’s legs and/or reference to a “fast” player.

Source – Major League Baseball