I am always interested in finding out where certain words or terms have come from. There are heaps in cricket - below are a few (the correctness of them all is debatable, but anyway). It may not be as comprehensive as the A to Z of Cricketing Terms, but what the hell.
Bosie - This term was used in the early 1900s in Australia to describe the wrong-un. It was so called in deference to B.J.T. Bosanquet, who is believed to be the inventor.
Googly - The English term for a wrong-un. So called because (evidently) it caused the batsman's eyes to goggle.
Popping Crease - Under the rules of cricket in the 1700s, a batsman had to place his bat into a hole cut in the turf to score a run. The wicketkeeper/fielders had to get the ball into the hole before the bat in order to affect a run-out. This hole was called the popping hole (as in popping the bat/ball into it), but after too many fielders had their fingers broken by the batsman slamming his bat into the hole at the same time as the fielder's hand, it was decided to change the hole to a line. The name popping hole then became popping crease.
Crease - After the popping hole went out the window, a crease (or furrow in the ground) was actually cut into the turf. This continued until the mid 1860s when they started using white paint.
Umpire - The word umpire evidently stems from the French 'nompere' which means 'not equal' or 'odd man'. This is to imply that the 'odd man' is called in to make decisions between two contestents.
Slips - The term slips comes from early times, with reference to these fielders covering 'slips from the bat'.
Point - This is a shortening of the phrase 'point of the bat', a position where the fielder stands close to the end of the bat.
Gully - Refers to the gap or 'gully' that exists between the slips and point
Cover - Refers to the position that 'covers' the point and middle of the wicket
Mid off and mid on - Shortenings of the terms 'middle wicket off' and 'middle wicket on'
Silly Mid On - the mid on is self explanatory, however it is believed that the silly refers to an old definition of silly, meaning 'defenceless'.
Third Man - This is so called because it was a position brought in with the advent of over-arm bowling, and the player supplemented the pre-existing positions of slip and point, thus being the 'third man' on the off-side.
Yorker - There are various different supposed meanings behind yorker. The one that seems to have reasonable credence relates to Tom Emmett, a highly successful Yorkshire bowler in the 1800s. He was very skilled at bowling full balls at the popping crease, and they became known as 'yorkers' because that is what batsmen had to cope with when they went to Yorkshire.
Maiden Over - While most people associated 'maiden' with female, another definition is 'unproductive'. Therefore, an unproductive over (i.e. one with no runs scored) became a maiden.
Wicket - Comes from the old english definition of a wicket being a small gate. Cricket is believed to have its origins with shephards, and very probably they used the gate on pens as the target to bowl at.
Bail - was originally a french word that described the top part of the gate of a sheep pen. See above re wicket.