As if the oceans needed more terrible news, scientists have learned that the coral reefs surrounding the Florida Keys are dissolving. The culpritâocean acidificationâwasnât expected to start hitting reefs hard for another three decades.
index noun (LIST) C1 [ C ] an alphabetical list, such as one printed at the back of a book showing which page a subject, name, etc. is on: Try looking up heart disease in the index. âº [ C ] a collection of information stored on a computer or on a set of cards, in alphabetical order:
Definition of indicator for English Language Learners. : 1  a sign that shows the condition or existence of something. : 2  a pointer or light that shows the state or condition of something. : 3  a device that shows a measurement.