Sr
       n 1: a soft silver-white or yellowish metallic element of the
            alkali metal group; turns yellow in air; occurs in
            celestite and strontianite [syn: strontium, atomic
            number 38]
       2: the unit of solid angle adopted under the Systeme
          International d'Unites [syn: steradian]
  sr.
       adj : used of the older of two persons of the same name especially
             used to distinguish a father from his son; "Bill Adams,
             Sr." [syn: elder, older]