bivalent /bī-vāˈlənt or bivˈə-lənt/

1. Having a valency of two (chem)
2. Relating to one of a pair of homologous chromosomes (also noun)

bivalence or bivalency noun

• Old Hundredth
• old identities
• old identity
• oldie
• oldies
• oldish
• Old Kingdom
• old ladies
• old lady
• Old Lady of Threadneedle Street
• Old Light
• old-line
• old-liner
• old-liners
• old maid
• old-maidhood
• old-maidish
• old-maidishly
• old-maidism
• old maids
• old man
• Old Man of the Mountain
• old man of the sea
• old man's beard
• old master