The word “stop”
Each of the first four lines is a clue to an anagram of “stop”.
The last line is a clue to the word itself.
line 1 – post (mail)
line 2 – pots (cooking utensils)
line 3 – tops (children’s toy)
line 4 – spot (perhaps from a dishwasher)
line 5 – stop (i.e. with faulty brakes)