1. A retrieving apparatus comprising: a first storing unit that stores a content; a second storing unit that stores a word dictionary in which a plurality of words are registered in association with readings of the words and each of the words representing a formal name and an abbreviated name of the formal name is registered in association with a family attribute among the words; a speech input unit that receives an input of a speech signal; a speech recognizing unit that recognizes a character string corresponding to the speech signal as a keyword; a retrieval-candidate expanding unit that retrieves a word coinciding with the keyword and a word familiar with the word from the word dictionary as a retrieval candidate word; a retrieval-word selecting unit that receives a selection designation that designates any of words included in the retrieval candidate words as a retrieval word; a retrieval-word expanding unit that sets the retrieval word and a word familiar with the retrieval word as expanded retrieval words, based on the word dictionary; and a retrieving unit that retrieves a content related to any of words included in the expanded retrieval words from the first storing unit.