IPA: /ˈsæn.ɪ.ti/
KK: /ˈsænɪti/
The state of having a healthy mind and being able to think clearly and make good decisions.
After a long day at work, she needed some time to relax and regain her sanity.
Sanity is derived from "sanus" (meaning healthy) in Latin, combined with the suffix "-ity" (meaning the state or condition of). Thus, the word "sanity" refers to the state of being healthy, particularly in a mental or psychological sense.
Think of 'sanus' meaning healthy, and remember that 'sanity' refers to the state of being mentally healthy.