bi·lat·er·al 
(bī-lătər-əl)
(bī-lătər-əl)adj.
1. Having or formed of two sides; two-sided.
2. Affecting or undertaken by two sides equally; binding on both parties: a bilateral agreement; bilateral negotiations.
3. Relating to both the right and the left side of the body or of a body structure: bilateral mastectomy.
4. Having or marked by bilateral symmetry.
bi·later·al·ism n.
bi·later·al·ly adv.
bi·later·al·ness n.