From Longman Dictionary of Contemporary Englishpersonal bestpersonal bestthe fastest time, most points etc that a sportsman or sportswoman has ever achieved I ran 20.51 seconds for a personal best. → personal
Examples from the Corpus
personal best• Conrad Allen came up trumps again, finishing fourth in the boys 800 metres in a personal best 2 mins. 22.• Fredericks' 19. 68 was 0. 14 seconds lower than his personal best.• That means that their motives are clean and their actions represent their personal best.• Sammy also collected a 50 freestyle bronze with 31.44-a personal best along with her 43.95 in the 50 breaststroke.• His personal best before this season was 10. 08.• Ron and I take each year as it comes and we always plan for me to run a personal best every season.• I next ran at Oslo where I set a personal best for 200 metres, so that was encouraging.• But I still ran 20.51 seconds for a personal best, so I was happy. 