Sentence:  A module consists of 21 <WSD>monolines</WSD>; a <WSD>monoline</WSD> on the other hand is 20 feet (6 m) long and consists of a nylon line plus 3 stakes— 2 at both ends and one at the middle— and 30 plants. 
Meaning of the word marked with <WSD> tags:  A length of monofilament line, used for culturing forms of seaweed.