What is Thick ?
Thick is (adj) 1. bigger than usual when measured from side to side, not thin He cut a slice of bread which was so thick it wouldn’t go into the toaster. The walls of the castle are three metres thick. Some oranges have very thick skins. He took a piece of thick rope. 2. close together They tried to make their way through thick jungle. The field was covered with thick grass. through thick and thin together, even when things are going badly (informal.) She stuck with him through thick and thin. they’re as thick as thieves (of two people) they are great friends, they share each other’s secrets 3. (of a liquid.) which cannot flow easily If the paint is too thick add some water. A bowl of thick soup is just what we need on a cold day like this. 4. which you cannot see through easily Thick fog had closed the airport. 5. stupid, not very intelligent (informal.) He’s a bit thick or as thick as two (short) planks. it’s a bit thick it’s not very fair It’s a bit thick, having to work on Saturdays when everyone else has the day off. (adv) thickly, in a thick way Put the plaster on thick so that it covers up the cracks. to lay it on thick to praise someone excessively (informal.) It was laying it on a bit thick to say that she plays the violin like Menuhin. thick and fast rapidly and often The faxes came in thick and fast. (noun) in the thick of something in the most active part of something in the thick of negotiations
source: Easier English, Student Dictionary Upper Intermediate Level