Sentence:  <WSD>ANFRACTUOSITY</WSD> (from Lat. anfractuosas, winding), twisting and turning, circuitousness; a word usually employed in the plural to denote winding channels such as occur in the depths of the sea, mountains, or the fissures (sulci) separating the convolutions of the brain, or, by analog, in the mind. 
Meaning of the word marked with <WSD> tags:  A winding channel or crevice, such as occur in the depths of the sea or in mountains.