12. A morpheme analyzer, comprising: an information acquirement unit configured to acquire a morpheme analysis target and additional information associated with the morpheme analysis target, from search index data; a key creator configured to create a key based on the additional information in response to the information acquirement unit acquiring the additional information; and a morpheme analyzing unit configured to analyze a morpheme of the morpheme analysis target by using the key, wherein the key creator comprises: a plural key creator configured to create a plurality of keys by performing a morpheme analysis for each information included in the additional information; and a combined key creator configured to create a combined key by combining the plurality of keys, and wherein the morpheme analyzing unit comprises: a determination unit configured to determine whether the morpheme analysis target includes a partial character string corresponding to the key; and a partial character string adder configured to temporarily add the partial character string in a morpheme dictionary in response to determining that the morpheme analysis target includes the partial character string corresponding to the key.
15. The morpheme analyzer of claim 12 , wherein the combined key creator creates the combined key by combining the first key and the second key, and the morpheme analyzing unit analyzes the morpheme of the morpheme analysis target by using the created combined key.