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: ocean 
Words: signal, timely, brine, flow, current
timely

Category: boats 
Words: hull, deck, rudder, check, lifeline
check

Category: poker 
Words: hull, blind, deck, chips, check

hull