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

In the movie, a young woman named Heather (Alexandra Daddario) learns that she’s actually adopted and her biological grandmother has died. —Keith Langston, PEOPLE, 25 Oct. 2025

The fouling problem worsens in warm climates, where biological activity peaks year-round. —Tejasri Gururaj, Interesting Engineering, 24 Oct. 2025

Scientists are working to grow real biological teeth in a human jaw. —Alexandra Banner, CNN Money, 24 Oct. 2025

The original photo was taken by California Family Council Outreach Director Sophia Lorey at a state playoff game that included a biological male trans athlete competing. —Jackson Thompson, FOXNews.com, 24 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