A word there is of plural number, 
Foe to ease and tranquil slumber,
Any other word you take, 
And add an s will plural make. 
But if you add an s to this, 
So strange the metamorphosis; 
Plural is plural now no more, 
And sweet what bitter was before. 

What word is referred to in this riddle?

*** Originally appeared in a collection composed by William S. Walsh in 1892

(In reply to spoiler by Ady TZIDON)

The collection, for which this riddle-poem may be part may be correctly attributed, yet William S. Walsh is not the riddle-poem's author, and the collection may not be the publication of the puzzle-rhyme's first appearance. Instead, the riddle-poem is noted to have been composed by George Canning (1770-1827), a British statesman and Prime Minister.

The literary solution given by Mr. Canning for his riddle-poem is
     "Though bitter cares the wearied mind enthral,
      Yet one fond sweet caress can banish all."

Edited on July 3, 2015, 1:52 pm

Posted by Dej Mar on 2015-07-03 09:21:50