Quick homework help? super easy?!!?

im doing a "reverse crossword puzzle" in my health book (the words are about alcohol and drugs) and i have to right clues for the answers. 5 of the words i dont even know. so my questions are: 1) what does "PCP" stand for? 2) what is "barbiturate"? 3) what is "hallucinogen"? 4) what is "amphetamines"? and 5) can i have a clue for "nicotine"? please help?!! its only 6th grade stuff!! 10 points to whoever answers all/most of them!! thanks!:)