A fungo bat is a specially designed bat used by baseball and softball coaches for practice. The etymology of the word fungo ( /ˈfʌŋɡoʊ/) is uncertain, but the Oxford English Dictionary suggests it is derived from the Scots fung: to pitch, toss, or fling.[26] A fungo is longer and lighter than a regulation bat, with a smaller diameter. The bat is designed to hit balls tossed up in the air by the batter, not pitched balls.[27] Typical fungo bats are 35 to 37 inches (89 to 94 cm) long and weigh 17 to 22 ounces (480 to 620 g). Coaches hit many balls during fielding practice, and the weight and length allow the coach to hit balls repeatedly with high accuracy. The small diameter also allows coaches to easily hit pop-ups to catchers and infielders along with ground balls due to better control of the barrel of the bat.
On June 17, 1890, Emile Kinst patented the ball-bat, or banana bat. The bat is shaped with a curve, hence the name banana bat. The creator of the bat, Kinst wrote: "The object of my invention is to provide a ball-bat which shall produce a rotary or spinning motion of the ball in its flight to a higher degree than is possible with any present known form of ball-bat, and thus to make it more difficult to catch the ball, or if caught, to hold it, and thus further to modify the conditions of the game".
Players can be very particular about their bats. Ted Williams cleaned his bats with alcohol every night and periodically took them to the post office to weigh them. "Bats pick up condensation and dirt lying around on the ground," he wrote, "They can gain an ounce or more in a surprisingly short time." Ichiro Suzuki also takes great care that his bats do not accumulate moisture and thus gain weight: he stores his bats in humidors, one in the club house and another, a portable one, for the road. Rod Carew fought moisture by storing his bats in a box full of sawdust in the warmest part of his house. "The sawdust acts as a buffer between the bats and the environment," he explained, "absorbing any moisture before it can seep into the wood."[25]

The origin of the word "fungo" is unknown and argued upon as there are many possible options as to the origins of this unique word. It is assumed by many to be derived from the Scottish word fung meaning to pitch, toss, or fling. This would make sense, as fungo bats are designed to do just that. Or, the alternative to this origin is that fungo comes from 1937 where David Shulman, writer for the American Speech, said, "My guess is that the word, which is baseball slang, may be explained through the elements of a compound word, fun and go." Lastly, a third belief is that the word fungo comes from an old game, similar to that of baseball, where the players used to chant, "One go, two goes, fun goes." 
For starters, we should clarify just what we’re talking about when we say fungo bat. Longer, lighter and thinner than a regulation bat (but a larger barrel), a fungo bat is typically 35 to 37 inches long, and weighs between 17 and 22 ounces. As David Allison wrote in the June 1978 edition of Country Journal, “A fungo bat looks to be a cross between a baseball bat and a broomstick.”