S: (v) prevent (prevent%2:41:00::), keep (keep%2:41:01::) (stop (someone or something) from doing something or being in a certain state) "We must prevent the cancer from spreading"; "His snoring kept me from falling asleep"; "Keep the child from eating the marbles"
W: (n) block (block%1:06:01::) [Related to: block] (an obstruction in a pipe or tube) "we had to call a plumber to clear out the blockage in the drainpipe"