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 of biological

• birth
• natural
• legitimate

Examples of biological in a Sentence

the rights of the biological father in this case

Recent Examples on the Web

Like the vast, uncaring jungle in Joseph Conrad's Heart of Darkness, the Tyranids are an irresistible force that seeks to surround and destroy humanity through the weight of pure biological necessity. —Alan Bradley, Space.com, 8 Nov. 2025

Carrie, meanwhile, is villainized for her admittedly deluded quest to reunite with her biological son in a world that has dismissed them. —Hunter Ingram, Variety, 8 Nov. 2025

The final scenes of the limited series reveal that Carrie is Milo's biological mother. —Emily Blackwood, PEOPLE, 8 Nov. 2025

She was delivered via surrogacy and is the first biological child for Lucas and Hobson. —Sari Hitchins, Parents, 7 Nov. 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