1. A word recognition apparatus for use with a character recognition system, comprising: a. word storing means for storing a plurality of words to be retrieved in block units in the order of block numbers so that characters placed in one or more given positions of a word forming an input character string are used as a retrieving key corresponding to one of said block numbers; b. block-starting-address storing means for storing starting addresses of the block units in said word storing means; c. block-starting-address and limit-address taking-out means for taking out a block starting address and a block limit address corresponding to a block number next to the designated block number from the block-starting-address storing means; d. input-character-string storing means for storing the input character string recognized by said character recognition system; e. block-number determining means for sequentially designating the block numbers of blocks containing words having recognized characters placed in said given positions of said input character string; f. word taking-out means for sequentially taking out words stored in the addresses from the block starting address of said word storing means to an address short of said block limit address by using the starting address and the block limit address which are taken out from the block-starting-address storing means with a block number used as the retrieving key; and g. word comparing means for detecting a word similar to the input character string to a degree over a given value by the comparison of the words thus taken out with said input character string.