placket

Short definition from Wiktionary

Noun

1. 1
   A slit or other opening in an item of clothing, to allow access to pockets or fastenings
2. 2
   A petticoat, especially an underpetticoat.
3. 3
   A woman.
4. 4
   A woman's pocket.
5. 5
   A leather jacket strengthened with strips of steel.
6. 6
   An additional plate of steel on the lower half of the breastplate or backplate.