noun (usually used with a singular verb)
the philosophy of ethics dealing with the meaning of ethical terms, the nature of moral discourse, and the foundations of moral principles.
Origin of metaethics
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
(functioning as singular) the philosophical study of questions about the nature of ethical judgment as distinct from questions of normative ethics, for example, whether ethical judgments state facts or express attitudes, whether there are objective standards of morality, and how moral judgments can be justified
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012