SG Heritage Dictionary

Plack [Noun] Webster's Dictionary 1913

A small copper coin formerly current in Scotland, worth less than a cent.

Placket [Noun] Webster's Dictionary 1828

A petticoat. If this is the sense of the word in Shakespeare, it is a derivative. The word signifies the opening of the garment; but it is nearly or wholly obsolete.

Placket [Noun] Webster's Dictionary 1913

1. A petticoat, esp. an under petticoat; hence, a cant term for a woman.

2. The opening or slit left in a petticoat or skirt for convenience in putting it on; -- called also placket hole.

3. A woman's pocket.