The phrase "liquid layer" refers to a thin, wet or damp coating of a liquid substance that covers a surface. It means there is a thin layer of liquid present. Full definition
In many foods, the high - speed spin concentrates the flavor molecules in a powerfully aromatic liquid layer that is ideal for cooking. (scientificamerican.com)
When thoroughly chilled, being careful not to shake, open up the two cans of straight coconut milk and (depending on whether you have opened the can with the cream or liquid layer at the top) either tip off the coconut water into a glass and scoop out the coconut cream that is left into a bowl, or scoop the coconut cream off the top to a bowl and pour the leftover coconut water into a glass (save the coconut water to drink or put in a smoothie). (glutenfreealchemist.com)
When the coated sheets of plastic are hung up like drying laundry, the thin liquid layer flows towards the ground, pulling the nanometre - thick sheets of clay into alignment with one another like neatly laid bricks. (newscientist.com)