sr

Noun sr has 2 senses

• sr(n = noun.substance) atomic number 38, strontium - a soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite;
is a kind of metal, metallic element
has particulars: strontium 90

• sr(n = noun.quantity) steradian - the unit of solid angle adopted under the Systeme International d'Unites;
is a kind of angular unit
is a part of sphere