Jaynee mack

exp.

An expression of wonder.

In use

Jaynee mack boy, yer wan gave me a right seein tew last night, so she did!

Let Lawrence Muck translate it to posh English for you
Lawrence Muck

Ahoy there. Nautical, I know. Would you like me to translate 'Jaynee mack' in use for you?

Goodness gracious, old boy, that young lady gave me a thorough seeing to last night, she most certainly did!