Anorak:
“Anorak” /ˈænəræk/ is a British slang term which refers to a person who has a very strong interest, perhaps obsessive, in niche subjects. This interest may be unacknowledged or not understood by the general public. The term is sometimes used synonymously with “geek” or “nerd“, or the Japanese term “otaku“, albeit referring to different niches. [Wikipedia]
Noted in “Why are rich people so boring?” Rachel Tashjian, WaPo:
But De Sarno showed tank tops and jeans. He covered coats with pretty twists of beads that would relegate them to special occasions only, and paired suit jackets with universally unflattering bunched tulip miniskirts. Decent outerwear was nonsensically slashed just below the breast; there were oddball lingerie dresses and a couple of hmmm raffia skirt suits. At the end, there was a strange series of anorak coats with enormous trains worn over a reprisal of jeans and tank tops.
Perhaps a different usage?