Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Category: type of sandwich 
Words: hoagie, burger, hamburger, club, discothek
discothek

Category: nutritional value 
Words: vitamin c, salt, sugar, fat, big boned
big boned

Category: social gathering 
Words: group, dance hall, club, outing, dagwood

dagwood