Thickest

Relatively great in extent from one surface to the opposite in its smallest solid dimension.

Measuring a certain number of units in this dimension.

"I want some planks that are two inches thick."

Heavy in build; thickset.

"He had such a thick neck that he had to turn his body to look to the side."

Densely crowded or packed.

"We walked through thick undergrowth."

In a thick manner.

"Snow lay thick on the ground."

Frequently or numerously.

"The arrows flew thick and fast around us."