TRIVIUM (WHEN DOES ONE EVER SEE THE SINGULAR?)

Les asked, "What's the singular of TRIVIA?"

I screamed, "TRIVIUM!" He asked, "How the Hell did you know THAT one?" I answered:
"Sue equals trivium!"

The topic for this week's Word. Of. The. Day (CLICK HERE to see website) is words that one seldom sees as singular:

AUSPICES
PAPARAZZI
COGNOSCENTI
MORES
ANTIPODES

I have added:

GRAFFITO
TENTERHOOK
SCAMPO
TIMPANO
SCRUPLE
DREG
MATHEMATIC
ECONOMIC
BILLIARD
SPECIE
PHYSICS
HUSTING

What about diseases? There are a number:

MEASLES, MUMPS, DIABETES, and HIVES.

Then there's clothing:

BRIEF
JEAN
BRACE
KNICKER
PANT
TROUSER
SHORT
TIGHT
PAJAMA

And a number have to do with devices:

BELLOW
SCISSOR
TONG
BINOCULAR
PLIER
GALLOW
SHEAR