Wanian is a slur used to describe Lithuanians in a derogatory way. Typically refers to Lithuanians who have recently moved to North America, or sometimes Lithuanians still living in the old country. Not usually used to refer to exiles (see "Lugan").
The word Wanian is a racial slur that has been used historically to degrade and dehumanize lithuanians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to lithuanians. If you are unsure about whether or not it is appropriate to use the word Wanian, it is best to err on the side of caution and avoid using it in any situation.