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

Lewkowitz described the biological struggle of the cotton plant, noting that the finest fibers are often the result of the plant evolving to survive stress. —Arthur Zaczkiewicz, Footwear News, 27 Apr. 2026

Future bots could help design and carry out biological, nuclear, and chemical warfare. —Matteo Wong, The Atlantic, 27 Apr. 2026

Studley explained the biological process responsible for the lobster’s two-toned appearance. —Hanna Wickes, Kansas City Star, 27 Apr. 2026

The authors note how of the 140,000 synthetic chemicals that are currently registered, only 1,000 are known to affect the biological processes that govern hormones, known as the endocrine system. —Tristan Bove, Fortune, 27 Apr. 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
• axiological
• climatological
• deontological
• dermatological
• eschatological
• etiological
• etymological

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