Decay time (of a pulse)
The interval between the instants at which the instantaneous value of a pulse or of its envelope (if a carrier frequency pulse is concerned) reaches specified upper and lower limits, namely 90% and 10% of the peak value unless otherwise stated.
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