12. A server comprising hardware configured to perform operations comprising: obtaining two words to be identified; determining that a shortest edit distance between the two words is less than or equal to an edit distance threshold; determining whether both of the two words exist in a preset knowledge database; if at least one of the two words does not exist in the preset knowledge database, segmenting one or more unfound words; determining whether all of the words after segmentation exist in the knowledge database; and if all of the words after segmentation exist in the knowledge database, finding a smallest granularity type with highest weight value for each such word in the knowledge database; and if both of the two words exist in the preset knowledge database, finding the smallest granularity type with highest weight value for each word in the knowledge database; determining whether the two words have a same smallest granularity type with highest weight value; if the two words have the same smallest granularity type with highest weight value, determining that the two words are synonyms; and if the two words do not have the same smallest granularity type with highest weight value, determining that the two words are non-synonyms.
16. A server as recited in claim 12 , wherein the operations further comprise, in responsive to determining that the two words are synonyms, saving such identified synonyms in a synonym database.