slot machine [1]
Electronic or mechanical gambling machine that is operated by inserting a coin into a slot in order to obtain a sequence of winning symbols.
reel 
Cylinder inscribed with symbols that is activated by the machine’s lever; when the three reels stop, the symbols line up to create a combination.
winning line 
Display showing the combinations of winning symbols and the winnings to be paid.
coin slot 
Opening through which coins are inserted into the machine in order to play.