DUMP- decrease in price
pump and dump are not just increase-decrease or dramatic increase-decrease.
pump and dump is the fake and manipulative increase and decrease of price respectively. for example when a fake pumping group buys first and then tells the idiots to start buying and they run to obey that is a pump. and when they dump on their heads to take the big profit and get out, that is a dump.
p.s. here are two good links on bull and bear markets:
http://www.investopedia.com/terms/b/bullmarket.asp
http://www.investopedia.com/terms/b/bearmarket.asp
and of course the basics: http://www.investopedia.com/articles/basics/03/100303.asp for more information