slip in

:  to move with a smooth sliding motion

:  to move quietly and cautiously :  steal

:  elapse, pass

:  a sloping ramp extending out into the water to serve as a place for landing or repairing ships

:  a ship's or boat's berth between two piers

:  the act or an instance of departing secretly or hurriedly

:  a small shoot or twig cut for planting or grafting :  scion

:  descendant, offspring

:  a long narrow strip of material

:  to take cuttings from (a plant) :  divide into slips

:  a mixture of finely divided clay and water used especially by potters (as for casting or decorating wares or in cementing separately formed parts)