semisynthetic

adjective

semi·​syn·​thet·​ic ˌse-mē-sin-ˈthe-tik 

ˌse-ˌmī-, 

-mi-

1

: produced by chemical alteration of a natural starting material

semisynthetic penicillins

2

: containing both chemically identified and complex natural ingredients

a semisynthetic diet

3

: partly synthetic

semisynthetic motor oil

Examples of semisynthetic in a Sentence

Recent Examples on the Web

Buprenorphine, semisynthetic opioid medication used primarily to treat opioid use disorder (OUD) and to manage severe chronic pain. — Encyclopedia Britannica, 28 Aug. 2026

The drinks could not be derived from marijuana or synthetic or semisynthetic cannabinoids. — The Denver Post, Denver Post, 2 May 2026

Given their findings, the authors urge more research on both natural kratom and semisynthetic 7-OH. — Kristen Rogers, CNN Money, 27 Mar. 2026

John Chavez of Bridge the Gap Botanicals in Boise, one of the largest bulk and retail suppliers of kratom in Idaho, said 7-hydroxymitragynine, also known as 7-OH, a semisynthetic compound derived from kratom, is the problem. — Angela Palermo, Idaho Statesman, 20 Mar. 2026

Word History

First Known Use

1937, in the meaning defined at sense 1

Rhymes for semisynthetic

• aeromagnetic
• antiemetic
• antipathetic
• apologetic
• biogenetic
• biomimetic
• biosynthetic
• cytogenetic
• diagenetic
• diamagnetic
• diaphoretic
• epigenetic

Medical Definition

semisynthetic

adjective

semi·​syn·​thet·​ic -sin-ˈthet-ik 

1

: produced by chemical alteration of a natural starting material

semisynthetic penicillins

2

: containing both chemically identified and complex natural ingredients

a semisynthetic diet

semisynthetically

-i-k(ə-)lē 

adverb