Did a quick search to try to find many of the common slang words used in metal detecting lingo to put into an easy to read list form.
If any corrections or additions are needed please feel free to do so, thanks !
Archie – An Archaeologist.
Barber - The Barber dime (named for its designer, Charles E. Barber, who was Chief Engraver of the U.S. Mint from 1879 to 1917.
cache - Coins or jewelry found together often in a jar.
canslaw - Shreds of aluminum cans left after being hit by a lawnmower.
clad - coins after 1964 that were cheaper metal covered (clad) to still look like silver coins except on the edge.
coinspill - a bunch coins found together in the same dig
key date – A coin of low mintage numbers that has higher value.
Merc - a Mercury dime (minted from 1916 to 1945)
plug - A hole carefully dug in the ground so that the grass is not harmed.
rosie - A silver Rosevelt dime (1946-1964)
seeded hunt - A hunt where the the finds have been scattered or planted
tear-outs - when sidewalks or parking lots are removed for repair or construction.
test garden - an area usually in one’s own yard with coins and other objects to test your detector's response to those items
toasted - A coin that is badly corroded because of a long period of time in the ground.
tot-lot - public playgrounds
Walker - US Walking Liberty Half Dollar (1916-1947)
wheatie - US wheat back cent (1909-1958)
.....and of course the infamous
Zincoln 
In 1982, with the 95% copper and 5% tin & zinc composition costing too much to produce, the United States Mint was approved to use a new metal composition for the penny:
97.5% zinc
2.5% copper
A lighter weight of 2.5 grams (versus 3.11 grams for the copper cent)
That combination results in a zinc core for the cent with a pure copper coating. 
I know, it’s actually a winged cap.
The design is a little bit of both, Liberty and Mercury.
