i Register
In some senses, m'lady is marked as historical, humorous. Watch for register when choosing this word.
noun
My Lady (used to address peers temporal, judges, etc).
verb
To address as “m’lady”.
[…]when people living in the same social set m’lorded and m’ladied each other with much frequency.
[…]lavishly “M’Ladyed,” as was the fashion of the day.