Found this great piece on the terms that baffle most of us.

Acid/Acidity:
Stuff that makes wine taste sharp.
Also contributes to
the bouquet and brilliance.
Can have too much or too little.

Acrid:
Describes a wine
with overly pronounced acidity.
This is often apparent in cheap red wines.

Aeration:
The process of letting a wine “breathe”.

Aftertaste:
The taste or flavors that linger
in the mouth after the wine is
tasted, spit, or swallowed.