noun /ˈdɪkʃən(ə)ɹi,ˈdɪkʃənɛɹi/
a) A reference work with a list of words from one or more languages, normally ordered alphabetically and explaining each words meaning and sometimes containing information on its etymology, usage, translations and other data.
b) An associative array, a data structure where each value is referenced by a particular key, analogous to words and definitions in a physical dictionary. ,
Wikipedia foundation.