Alky, drunkard, drunk, boozer. Derived from a truncated version of the noun алкоголик (alcoholic). Chronic drinker, someone who is frequently intoxicated, or a person exhibiting a stereotypical down-and-out lifestyle due to alcohol abuse (на скамейке опять спят какие-то алкаши — “there are some alkies sleeping on the bench again”).
Вообще, у меня сложилось ощущение, что это неудовлетворенный жизнью амбициозный алкаш.
In all I got the impression that he is an ambitious drunkard frustrated by life.
(Фёдорыч, 02/2012)

