Photoluminescence which persists for an appreciable time after excitation.
Note: This time is generally more than about 10-8 second.
Reference: C.I.E. (extract)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM