ETYM Old Fren. riere behind, backward, from Latin retro. Related to Arrear.
1. The back of a military formation or procession.
2. The side of an object that is opposite its front; SYN. backside, back end.
3. The side that goes last or is not normally seen; SYN. back.
spine / spaɪn /
ETYM Latin spina thorn, the spine; akin to spica a point: cf. Old Fren. espine, French épine. Related to Spike, Spinet a musical instrument, Spinny.
A sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin.
The backbone of vertebrates. It consists of separate disk-shaped bony units (vertebrae), processes that enclose and protect the spinal cord. The spine connects with the skull, ribs, back muscles, and pelvis.
In humans, there are seven cervical vertebrae in the neck; 12 thoracic in the upper trunk; five lumbar in the lower back; the sacrum (consisting of five vertebrae fused together, joined to the hipbones); and the coccyx (four vertebrae, fused into a tailbone). The human spine has four curves (front to rear), which allow for the increased size of the chest and pelvic cavities, and for a degree of spring so as to minimize jolting of the internal organs.