quintile

noun

1. equally divided into 5 groups

2. an aspect of 72° (one fifth of a circle).



reference:
https://www.google.com/search?q=quintiles+meaning&oq=quintiles&aqs=chrome.2.69i57j0l7.3245j0j7&sourceid=chrome&ie=UTF-8


found in:
https://www.ashp.org/-/media/assets/policy-guidelines/docs/draft-guidelines/draft-guidelines-ASHP-IDSA-PIDS-SIDP-therapeutic-vancomycin.ashx