den·dro·chro·nol·o·gy 
(dĕn′drō-krə-nŏlə-jē)
(dĕn′drō-krə-nŏlə-jē)n.
The study of climate changes and past events by comparing the successive annual growth rings of trees or old timber.
den′dro·chron′o·logi·cal (-krŏn′ə-lŏjĭ-kəl) adj.
den′dro·chron′o·logi·cal·ly adv.
den′dro·chro·nolo·gist n.