Thick
Part of speech: adverb
Definition: In a thick manner. Thickly.
Part of speech: noun
Definition: The thickest, or most active or intense part of something.
Part of speech: adjective
Definition: Relatively great in extent from one surface to the opposite in its smallest solid dimension. Measuring a certain number of units in this dimension. Heavy in build; thickset. Densely crowded or packed. Having a viscous consistency. Abounding in number. Impenetrable to sight. Difficult to understand, or poorly articulated. Stupid. Friendly or intimate. Deep. intense, or profound.
Example sentence: I'm as thick as a plank.
Impenetrable
Part of speech: adjective
Definition: not penetrableincomprehensible; inscrutable