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: aesthetic characteristic 
Words: fine, custody, level, beautiful, attractive
custody

Category: bird 
Words: concrete pourer, flamingo, egret, crane, duck
concrete pourer

Category: baby animals 
Words: cub, colt, fawn, woo, bambi

woo