Histories of lexicography acknowledge that the original purpose of English dictionary-making was pedagogical. Although children's dictionaries are widely regarded as a 20th-century genre, several dictionaries were specifically developed for children as early as the 18th and 19th centuries. Moreover, these dictionaries were ideologically adapted for child readers with the aim of providing social and moral education. This article explores one facet of the ideological adaptation of 19th-century children's dictionaries, namely sexuality. Creating children's dictionaries involves choices about the selection of headwords, the inclusion of word senses, and the wording of definitions. Such choices were not only guided by space constraints and ideas about children's intellectual capacities, but also by conceptions about appropriate and inappropriate material for children. 19th-century compilers of children's dictionaries employed "politeness strategies," which could involve omitting parts of a definition, word senses, or even entire semantic fields related to sexuality. Moreover, dictionaries aimed at children from various social and religious backgrounds constructed the child reader differently in terms of innocence and/or corruption.