An alcoholic is someone that has a constant craving for alcoholic beverages. It is overwhelming for them to try to go without alcohol.
Alcoholism is often associated with chronic depression. It can and very often does accentuate that depression and makes it even more difficult to treat. Alcoholics that begin a treatment for alcoholism and depression will many times choose the alcohol over the medication, or worse, take both.
Alcoholics, when not inebriated, are usually in a state of "stand by" inebriation, and it takes only a small amount of an alcoholic beverage to get them inebriated and to make the symptoms of inebriation detectable.
They will rarely act as a drunkard does, instead being more introverted and somewhat contained. An alcoholic will always persistently lie and deny that he or she has consumed any alcohol even when the symptons make it obvious that he/she did and they may often pretend that they're under the effect of some medication or simply sleepy as an excuse for their lack of balance and for tripping on words.
YOU'RE NOT AN ALCOHOLIC, YOU'RE A DRUNKARD! ;)