[dic.tio.nary] n, pl -nar.ies [ML dictionarium, fr. LL diction-, dictio word, fr. L, speaking] (1526) 1: a reference book containing words usu. alphabetically arranged along with information about their forms, pronunciations, functions, etymologies, meanings, and syntactical and idiomatic uses
2: a reference book listing alphabetically terms or names important to a particular subject or activity along with discussion of their meanings and applications
3: a reference book giving for words of one language equivalents in another
4: a list (as of items of data or words) stored in a computer for reference (as for information retrieval or word processing)