the time required for something to fall to half its initial value (in particular, the time for half the atoms in a radioactive substance to disintegrate)
unit of heat defined as the quantity of heat required to raise the temperature of 1 gram of water by 1 degree centigrade at atmospheric pressure
a unit of heat equal to the amount of heat required to raise the temperature of one kilogram of water by one degree at one atmosphere pressure; used by nutritionists to characterize the energy-producing potential in food
(theology) the origination of the Holy Spirit at Pentecost; "the emanation of the Holy Spirit"; "the rising of the Holy Ghost"; "the doctrine of the procession of the Holy Spirit from the Father and the Son"
something that is emitted or radiated (as a gas or an odor or a light etc.)
cartilaginous fishes having horizontally flattened bodies and enlarged winglike pectoral fins with gills on the underside; most swim by moving the pectoral fins
any of the stiff bony rods in the fin of a fish
a branch of an umbel or an umbelliform inflorescence
(mathematics) a straight line extending from a point
emit as rays; "That tower rays a laser beam for miles across the sky"