TASK DEFINITION: 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.
PROBLEM: Category: social gathering 
Words: group, dance hall, clan, club, dagwood

SOLUTION: dagwood

PROBLEM: Category: animal 
Words: fish, iguana, canyoning, hamster, horse

SOLUTION: canyoning

PROBLEM: Category: accomodation 
Words: mansion, mountain, flat, house, duplex

SOLUTION:
mountain