saponify

UK: /səˈpɒnɪˌfaɪ/ US: (sə pon′ə fī′)

WordReference Random House Unabridged Dictionary of American English © 2025

sa•pon•i•fy  (sə pon′ə fī′), v., -fied, -fy•ing. [Chem.]
v.t. 

1. Chemistry to convert (a fat) into soap by treating with an alkali.
2. Chemistry to decompose (any ester), forming the corresponding alcohol and acid or salt.

v.i. 

3. Chemistry to become converted into soap.

• Latin sāpōn- (stem of sāpō) soap + -ify
• 1815–25

sa•pon′i•fi′a•ble, adj. 
sa•pon′i•fi•ca′tion, n. 
sa•pon′i•fi′er, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

saponify / səˈpɒnɪˌfaɪ/ verb ( -fies, -fying, -fied)

1. to undergo or cause to undergo a process in which a fat is converted into a soap by treatment with alkali
2. to undergo or cause to undergo a reaction in which an ester is hydrolysed to an acid and an alcohol as a result of treatment with an alkali

Etymology: 19th Century: from French saponifier, from Latin sāpō soap

saˈponiˌfiable adjective

saˈponiˌfier noun

saˌponifiˈcation noun