sr

Multiple Entries:
  sr    Sr    steradian    strontium  

Concise Oxford English Dictionary © 2008 Oxford University Press:
sr

▶abbreviation steradian(s).

Concise Oxford English Dictionary © 2008 Oxford University Press:
Sr

▶abbreviation

• 1 senior (in names).

• 2 Señor.

• 3 Signor.

• 4 Sister (in a religious order).

▶symbol the chemical element strontium.

Concise Oxford English Dictionary © 2008 Oxford University Press:
steradian /stəˈreɪdɪən/ (abbrev.: sr)

▶noun the SI unit of solid angle, equal to the angle at the centre of a sphere subtended by a part of the surface equal in area to the square of the radius.

– origin C19: from Gk stereos ‘solid’ + radian.

Concise Oxford English Dictionary © 2008 Oxford University Press:
strontium /ˈstrɒntɪəm, ˈstrɒnʃ(ɪ)əm/

▶noun the chemical element of atomic number 38, a soft silver-white metal of the alkaline earth series. (Symbol: Sr)

– origin C19: from strontia + -ium.