middle-aged

US /ˌmɪd.əlˈeɪdʒd/
UK /ˌmɪd.əlˈeɪdʒd/
"middle-aged" picture
1.

being in the period of life between youth and old age, usually considered to be from about 45 to 65

:
My parents are both middle-aged.
The survey targeted middle-aged professionals.