at the top of the hour

:  the highest point, level, or part of something :  summit, crown

:  a garment worn on the upper body

:  the head of a plant

:  of, relating to, or being at the top :  uppermost

:  chief, leading

:  of the highest quality, amount, or degree

:  to be or become higher than :  overtop

:  to be superior to :  excel, surpass

:  to gain ascendancy over :  dominate

:  a commonly cylindrical or conoidal device that has a tapering point on which it is made to spin and that is used especially as a toy

:  a time or office for daily liturgical devotion

:  canonical hour

:  the 24th part of a day :  60 minutes