sa·pon·i·fy 
(sə-pŏnə-fī′)
(sə-pŏnə-fī′)v. sa·pon·i·fied, sa·pon·i·fy·ing, sa·pon·i·fies
v.tr.
1. To convert (an ester) by saponification.
2. To convert (a fat or oil) into soap.
v.intr.
To undergo saponification.
[French saponifier : Latin sāpō, sāpōn-, hair dye; see SAPONIN + French -fier, -fy.]
sa·poni·fi′a·ble adj.
sa·poni·fi′er n.