■ noun ( plural diaries ) a book in which one keeps a daily record of events and experiences.
↘ Brit. a book with spaces for each day of the year in which to note appointments.
Word History
As well as being synonyms, ~ and journal come from the same Latin word, dies 'day'. The older word journal came into English in the 14th century from Old French jurnal , from Latin diurnalis 'daily'; the later word ~ , which entered English in the 16th century, came directly from Latin diarium 'daily allowance', later '~'. Dial and dismal also derive from dies , the latter being a contraction of dies mali 'evil days'.