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

Researchers may have uncovered the biological pathway that causes this side effect. — Mark Gurarie, Verywell Health, 23 July 2026

By integrating these biological considerations into scheduling, leaders can achieve sustained performance and avoid chronic stress. — Luciana Paulise, Forbes.com, 23 July 2026

The findings, detailed in a study published today in the journal Science, trace the larva’s daily diving routine with a sonar system, and look at what is going on at the biological level. — Margherita Bassi, Popular Science, 23 July 2026

Adults with lower handgrip strength showed accelerated biological aging on epigenetic clocks, which measure DNA methylation to reveal a person’s true biological age. — Samantha Agate, Fort Worth Star-Telegram, 23 July 2026

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

• illogical
• zoological
• aetiological
• anthropological
• archaeological
• archeological
• axiological
• climatological
• deontological
• dermatological
• eschatological
• etiological

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