slip

   1. to give premature birth to

   Usually of domestic animals:

    Cows slipped their calves, horses fell lame. (R. Hunt, 1865)

   but not for the great diarist:

    Fraizer is so great with my Lady Castlemain and Steward and all the ladies at Court, in helping them slip their calfes when there is occasion. (Pepys, 1664 — Fraizer was a court physician and royal abortionist, without whom there might have been many more royal dukedoms)

   To slip a foot or slip a girth was to give birth to an illegitimate child, both with imagery from a fall whilst riding:

    Slipping a foot, casting a leglin-girth or the like. (W. Scott, 1822)

   2. to slip

   die

   The concept of gliding easily away and usually in compounds. To slip away is to die painlessly, usually in old age or after long illness:

    To 'slip away' within sight of ninety. (Maclaren, 1895)

   Old people may also slip off. With nautical imagery you may slip your breath, cable, grip or wind:

    He was going to slip his cable with all the good scandal untold. (Fraser, 1971)

   I don't think people slip to Nod any more:

    He the bizzy roun' hath trod, An' quietly wants to slip to Nod. (W. Taylor, 1787 — later in the verse his fate is to 'trudge on Pluto's gloomy shore')