Ru

Multiple Entries:
  Ru    RU    ruthenium  

Concise Oxford English Dictionary © 2008 Oxford University Press:
Ru

▶symbol the chemical element ruthenium.

Concise Oxford English Dictionary © 2008 Oxford University Press:
RU

▶abbreviation

• 1 Burundi (international vehicle registration). [from Ruanda-Urundi (now Rwanda and Burundi).]

• 2 rugby union.

Concise Oxford English Dictionary © 2008 Oxford University Press:
ruthenium /rʊˈθiːnɪəm/

▶noun the chemical element of atomic number 44, a hard silvery-white metal. (Symbol: Ru)

– origin C19: mod. L., from Ruthenia (see Ruthenian), because it was discovered in ores from the Urals.