Wiktionary
growth ring
n. Any of the concentric rings formed in the trunk of a tree by the annual growth of wood
WordNet
growth ring
n. an annual formation of wood in plants as they grow [syn: annual ring]
Usage examples of "growth ring".
The records from ice cores, isotope ratios in the shells of marine fossils, growth ring patterns in trees, and so forth show that at times when temperatures were high, carbon dioxide levels were high, and vice versa.
The record of the seasons was there, to be tediously read when properly keyed: every winter, every summer, every growth ring, for these changes were important to the Tree.