[First published 09/2016; substantive revision 02/2021.] Evaluative terms and concepts are often divided into “thin” and “thick”. We don’t evaluate actions and persons merely as good or bad, or right or wrong, but also as kind, courageous, tactful, selfish, boorish, and cruel. The latter evaluative concepts are "descriptively thick": their application somehow involves both evaluation and a substantial amount of non-evaluative description. This article surveys various attempts to answer four fundamental questions about thick terms and concepts. (1) A “combination question”: (...) how exactly do thick terms and concepts relate evaluation and non-evaluative description? (2) A “location question”: is evaluation somehow inherent to thick terms and concepts, such as perhaps an aspect of their meaning, or merely a feature of their use? (3) A “delineation question”: how do thick terms differ from the thin and from other kinds of evaluative terms? (4) Given answers to these questions, what broader philosophical significance and applications might thick concepts have? (shrink)