biological

adjective

bi·​o·​log·​i·​cal ˌbī-ə-ˈlä-ji-kəl 

variants or less commonly biologic

ˌbī-ə-ˈlä-jik 

1

: of or relating to biology or to life and living processes

2

: used in or produced by applied biology

3

: connected by direct genetic relationship rather than by adoption or marriage

her biological father

biologically

ˌbī-ə-ˈlä-ji-k(ə-)lē 

adverb

Synonyms

• birth
• legitimate
• natural

Examples of biological in a Sentence

the rights of the biological father in this case

Recent Examples on the Web

The ultrathin layer, developed by researchers led by Cho Jin-han, PhD, a professor at Korea University’s chemical and biological engineering department, prevents the formation of dangerous dendrites. —Georgina Jedikovska, Interesting Engineering, 17 Oct. 2025

Mutabazi later took to Instagram to share a video of their heartfelt exchange on the phone, noting that Isabella’s biological mother gave him permission to share the interaction with his followers. —Valerie Mesa, PEOPLE, 17 Oct. 2025

The polling on biological male participation in women's sports is even starker. —Josh Hammer, MSNBC Newsweek, 17 Oct. 2025

For Glass, an obvious red line is for scientists to refrain from making a mirror ribosome, a biological machine found in a cell’s cytoplasm that makes proteins. —Katie Hunt, CNN Money, 17 Oct. 2025

Word History

First Known Use

1818, in the meaning defined at sense 1

Phrases Containing biological

• biological clock
• biological control
• biological oxygen demand
• biological parent
• biological warfare
• biological weapon
• non-biological

Rhymes for biological

• analogical
• astrological
• christological
• chronological
• cosmological
• cytological
• dialogical
• ecological
• ethnological
• ethological
• geological
• histological

Kids Definition

biological

adjective

bi·​o·​log·​i·​cal

ˌbī-ə-ˈläj-i-kəl

variants also biologic

-ˈläj-ik

1

: of or relating to biology or to life and living things

2

: connected by a relationship involving heredity rather than by one involving adoption or marriage

his biological father

biologically

-ˈläj-i-k(ə-)lē

adverb

Medical Definition

biological

adjective

variants also biologic

1

: of or relating to biology or to life and living processes

2

: used in or produced by applied biology

3

: related by direct genetic relationship rather than by adoption or marriage

an adoptee who searched for years for her biological parents

biologically

-i-k(ə-)lē 

adverb