Here are common terminologies in the Vintage Watch Industry
Bezel--The top part of the case that surrounds the crystal
Brassing--When the case has been worn down through the gold fill or plate exposing the underlying metal, usually brass. See also "wear through" below.
CLD--Pronounced "sealed". Hamilton's early attempt at waterproofing a watch. Cases usually have a front opening bezel with a rubber gasket. This did not work very well.
Crystal--The glass or acrylic part. Originally many of these were glass when scratched they were unrepairable. Later watches had acrylic [plastic] which could be buffed out. Most replacement crystals are acrylic.
Dial--The "face" of the watch. These were usually silver on vintage hamiltons.
Gold Filled--A mechanical process of sandwiching a base metal with real gold. The layer of gold is thicker than "rolled gold plate", or "gold plate".
Hooded Lugs--When the metal of the case covers [or "hoods"] the connection of the band so the connection is not seen.
Jewels--Usually a synthetic red sapphire used in wear points to lessen friction.
Lugs--The protrusions at the ends of the bezel that the band pins and band attach to.
Markers--The painted or applied details on the dial which take the place of numbers.
Mint--An evaluation of the condition of the watch. This means that the watch is as originaly purchased. Can also refer to one part such as a "mint" dial.
NOS--New Old Stock--Sometimes original watches or parts are found in old inventories of dealers or watchmakers.
Redial--A redial is when the original dial is refinished. A professional refinisher will strip the old finish off of the dial and reapply all markings--hopefully back to original.
Sub second--When the second hand has a different location on the dial than the hour and minute hands. The sub seconds are usually in the "6" position.
Tank--Originaly, this referred only to the style of case which had an "H" shape. The shape looked like a military tank viewed from above. Now, this refers to all rectangular and square shaped cases.
Wear through--When the case has been worn through both the gold fill and the base metal. Sometimes this is just from wearing the watch over years. This can also occur because of the tension that the gold fill is under on sharp corners of the case--most usually the lugs.
