bi ‧ o ‧ lo ‧ gi ‧ cal /ˌbaɪəˈlɒdʒɪk ə l◂ $ -ˈlɑː-/ BrE AmE adjective
1 . relating to the natural processes performed by living things:
the biological functions of the body
Depression is both biological and psychological.
2 . biological weapons/warfare/attack etc weapons, attacks etc that involve the use of living things, including ↑ bacteria , to harm other living things:
a ban on chemical and biological weapons
3 . [only before noun] relating to biology:
the biological sciences
4 . biological parent/father/mother etc a child’s parent through birth, rather than through ↑ adoption
—biologically /-kli/ adverb