Definitions:
each of a series of slender curved bones articulated in pairs to the spine (twelve pairs in humans), protecting the thoracic cavity and its organs

a long raised piece of strengthening or supporting material.

a vein of a leaf or an insect's wing

a combination of alternate plain and purl stitches producing a ridged, slightly elastic fabric

mark with or form into ridges

tease good-naturedly

a small open boat with a fibreglass hull and inflatable rubber sides.