Photochemical process leading to the addition of water across a
C–C double (or triple) bond or to a carbonyl (or carbonyl analogue) group.
Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 392 (https://doi.org/10.1351/pac200779030293)