RACHIS

n. spinal column, backbone; axis

Rachis is also the alternate spelling of Ratchis, king of the Lombards, 744-749. The rachis (pronounced /ˈɹeɪkɪs/) is the main axis of the inflorescence, or spike, of wheat and other cereals, to which the spikelets are attached. It is also the part of the axis that the pinnae are attached to in ferns, the main stem of a compound leaf (such as in Acacia), or the main axis in compound inflorescences in other angiosperms.
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Noun
1. axis of a compound leaf or compound inflorescence
(hypernym) axis
2. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord; "the fall broke his back"
(synonym) spinal column, vertebral column, spine, backbone, back
(hypernym) skeletal structure
(hyponym) notochord
(part-holonym) axial skeleton
(part-meronym) spinal canal, vertebral canal, canalis vertebralis

n. rachis, spinal column, backbone; axis

n. night, period of time between sunset and sunrise

v. scratch, scrape, rub