va·de me·cum | \ ˌvā-dē-ˈmē-kəm
1 : a book for ready reference : manual
2 : something regularly carried about by a person
Brush Up on Your Latin With Vade Mecum
Vade mecum is Latin for go with me (it derives from the Latin verb vadere, meaning "to go.") In English, "vade mecum" has been used (since at least 1629) of manuals or guidebooks sufficiently compact to be carried in a deep pocket. But from the beginning, it has also been used for such constant companions as gold, medications, and memorized gems of wisdom.
First Known Use of vade mecum
1629, in the meaning defined at sense 1
History and Etymology
borrowed from Latin, "go with me"
THE NAUGHTY PREPOSITION
I lately lost a preposition
It hid I thought, beneath my chair
And angrily I cried: "Perdition!
Up from out of in under there!"
Correctness is my vade mecum,
And strangling phrases I abhor:
And yet I wondered: "What should he
come up from out of in under for!"
Vademecum contro il Coronavirus in salsa Rimbamband