Bivalent

• (biology) The complex formed by a pair of homologous chromosomes during meiosis I.
  Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row
• (geology)

1. Having a valence of 2. Webster 3rd
2. Having two valences; e.g., cobalt has two forms, with valences of 2 and 3, respectively. Handbook of Chemistry and Physics, 2
   Source: Dictionary of Mining, Mineral, and Related Terms