vade mecumEnglishOxford Dictionary of Englishvade mecum /ˌvɑːdi ˈmeɪkəm , ˌveɪdi ˈmeɪkəm , ˌvɑːdi ˈmiːkəm , ˌveɪdi ˈmiːkəm / ▸ noun a handbook or guide that is kept constantly at hand for consultation: his book is an excellent vade mecum for writers. – ORIGIN early 17th century: modern Latin, literally ‘go with me’.