brachi-, brachio-

(Greek: arm [especially the upper arm from the shoulder to the elbow])

tribrachia
Condition seen in conjoined twins when the fusion has merged the adjacent arms to form a single one, so that there are only three arms for the two bodies.
tribrachial
A figure or utensil with three arms, especially a three-branched flint.
tribrachius
A deformed fetus, usually conjoined twins, having three arms.
zoster brachilis
Herpes zoster affecting the arm or forearm.