When you get to thinking about oddities of words a string of peculiarities occur. Hence I make no apologies for continuing the theme.
There are many English words which only exist in the plural or do have a form without that final 's' but which has a different meaning or used in an utterly different context. I came up with the following list, any others?
Bellows, binoculars, forceps, gallows, glasses, pliers, scissors, shears, tongs, braces, briefs, jeans, knickers, pants, pyjamas, shorts, tights, trousers, economics, physics, ethics, entrails, hustings.