Where does “slūpan” come from?

slūpan (Old Dutch) comes from Proto-West Germanic *sleupan, from Proto-Germanic sleupaną, from Proto-Indo-European slewb(ʰ)- — to slip, glide.

Ancestry of “slūpan”, step by step

Step	Language	Word	Meaning
1	Proto-West Germanic	*sleupan	—
2	Proto-Germanic	sleupaną	To creep, slink, sneak, slip
3	Proto-Indo-European	slewb(ʰ)-	to slip, glide

slūpan — Etymology, Origin & Word History | Etymology Explorer