He then declared a 6-month moratorium on new deepwater drilling permits and leases, pending regulatory assessment. American Economic Review. 107 (9): 2565-2599. doi:10.1257/aer.20160812. In December 2009, the New Oxford American Dictionary declared its term of the calendar year to be the verb "unfriend", described as "To clear away anyone as a 'friend' on a social networking site this kind of as Facebook". American Antiquarian Society.