Sentence:  Next a marsh, it would seem, and now mere earth / Desperate and done with; (so a fool finds mirth, / Makes a thing and then mars it, till his mood / Changes and off he goes!) within a rood— / Bog, clay and rubble, sand and stark black <WSD>dearth</WSD>. 
Meaning of the word marked with <WSD> tags:  Scarcity; a lack or short supply.