Words that come from Proto-Indo-European slewb(ʰ)-

25 words across 8 languages descend from Proto-Indo-European slewb(ʰ)- — including slopen, slupen, sluipen, slūpan, slôpen, slōpen, slopen, sluipweg.

See the etymology of slewb(ʰ)- itself →

Dutch (11)

Middle Dutch (3)

Old Dutch (3)

German (3)

Proto-Germanic (2)

Old English (1)

Middle High German (1)

Old High German (1)