1570s, "wearing slippers or loose shoes," from slip (v.) + shod "wearing shoes." Sense of "slovenly, careless" is from 1815, probably from the notion of appearing like one in slippers, or whose shoes are down at the heels.
slipshod spelling
slip
slipknot
slippage
slipper
slippery
slipshod
slipstream
slit
slither
sliver
Sloane Square