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

The court ruled 6-3 to uphold state laws that protect women's sports from biological male trans athletes. — Jackson Thompson Outkick, FOXNews.com, 2 July 2026

Its projects span areas such as membrane separation, nanobubble technology, biological treatment processes, ion exchange, and advanced oxidation systems. — Jason Phillips, USA Today, 2 July 2026

There are a couple of biological facts that should be mentioned. — Jack G. Mell, Outdoor Life, 2 July 2026

Yes, and researchers now have a direct biological mechanism, not just a correlation. — Allison Palmer, Sacbee.com, 2 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