Citing budget concerns, the city council announced that it has deep-sixed plans to repave the city's bike trails.
“The nationalist and confrontational Putin has already made it clear that he intends to deep-six Mr. Medvedev's friendly and cooperative approach to the US, and to Obama in particular.” — From an article by Howard LaFranchi in The Christian Science Monitor, June 18, 2012
Before the introduction of shipboard sonar, water depth was measured by hand with a sounding line. This was generally a rope weighted at one end, with bits of leather called “marks” tied on at intervals to measure the fathoms. Between the marks, fathoms were estimated by “deeps.” The “leadsman” (pronounced LEDZ-mun) lowered the line into the water and called out the depth as the rope passed through his hands: “By the mark twain!” at two fathoms; “By the deep six!” at six fathoms. Perhaps due to an association with “six feet under” (dead and buried), to give something the “deep six” (or to “deep-six” it) was to throw it overboard, or, by extension, to discard it. In the mid-1960s “deep-six” made landfall; since then it has been used as much by landlubbers as by old salts.
From Merriam-Webster Online at www.Merriam-Webster.com.