Bilateral

pertaining to, involving, or affecting two or both sides, factions, parties, or the like:
a bilateral agreement; bilateral sponsorship.
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:
bilateral affiliation.
compare unilateral (def 7).
informal. a bilateral agreement, especially regarding international trade.
contemporary examples

how the chuck hagel fight changed the american jewish landscape in washington j. j. goldberg august 19, 2013
christine lagarde: can a woman save the imf? tracy mcnicoll may 31, 2011
italian pirate-fighting marines on trial barbie latza nadeau february 13, 2014
italy’s refugee camp horror barbie latza nadeau march 20, 2011
italian migrants sew mouths shut in protest barbie latza nadeau february 3, 2014

historical examples

manual of surgery volume second: extremities–head–neck. sixth edition. alexander miles
memoir of the life of john quincy adams. josiah quincy
area handbook for bulgaria eugene k. keefe, violeta d. baluyut, william giloane, anne k. long, james m. moore, and neda a. walpole
report on the radiolaria collected by h.m.s. challenger during the years 1873-1876, first part: porulosa (spumellaria and acantharia) ernst haeckel
elementary zoology, second edition vernon l. kellogg

adjective
having or involving two sides
affecting or undertaken by two parties; mutual: a bilateral treaty
denoting or relating to bilateral symmetry
having identical sides or parts on each side of an axis; symmetrical
(sociol) relating to descent through both maternal and paternal lineage compare unilateral (sense 5)
(brit) relating to an education that combines academic and technical courses
a bilateral meeting
adj.