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

There were also some declines seen in certain drugs, with lower rates reported for heroin, natural and semisynthetic opioids, and methadone. —CBS News, 22 Mar. 2024

Between 2021 and 2022, the death rate involving synthetic opioids other than methadone -- such as fentanyl -- increased by 4.1% from 21.8 per 100,000 to 22.7 per 100,000, while rates for deaths involving heroin, natural and semisynthetic opioids and methadone declined. —Mary Kekatos, ABC News, 20 Mar. 2024

The rate of drug overdose deaths involving heroin, natural and semisynthetic opioids and methadone were lower in 2018 than the previous year. —Janet Adamy, WSJ, 30 Jan. 2020

Hydrocodone and oxycodone are semisynthetic opioids used to treat pain. —Author: Lindsey Bever, Anchorage Daily News, 1 Feb. 2018

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