Spit Nails Meaning

Example : 1965 Sep. 6, Ann Landers, "Exception is Acknowledged," Spokane Daily Chronicle, p. 17 (retrieved 22 Nov 2013):  [O]ne thing about Aunt Jenny gets me so mad I could spit nails.1993 Nov. 9, "RAF chief attacks Treasury over cuts," The Independent (UK) (retrieved 22 Nov 2013):  The three chiefs of staff are described by sources as ‘spitting nails’ over the latest proposals to cut the defence budget even further.2009 Dec. 14, David M. Herszenhorn and David D. Kirkpatrick, "Lieberman Gets Ex-Party to Shift on Health Plan," New York Times (retrieved 22 Nov 2013):  Just the thought of Joseph I. Lieberman makes some Democrats want to spit nails these days. But Mr. Lieberman, the Connecticut independent, is not the least troubled by his status as Capitol Hill’s master infuriator.