E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Meum and Tuum.
That which belongs to me and that which is anothers. Meum is Latin for what is mine, and tuum is Latin for what is thine. If a man is said not to know the difference between meum and tuum, it is a polite way of saying he is a thief.
Meum est propositum in taberna mori. A famous drinking song by Walter Mapes, who died in 1210.