bilateral

pertaining to, involving, or affecting two or both sides, factions, parties, or the like:

located on opposite sides of an axis; two-sided, especially when of equal size, value, etc.

Biology. pertaining to the right and left sides of a structure, plane, etc.

Chiefly Law. (of a contract) binding the parties to reciprocal obligations.

through both parents equally: Compare unilateral ( def 7 ).

Informal. a bilateral agreement, especially regarding international trade.