The Angle-Friesish nosely narrowloud law is the law in speechlore by which Friesish and English lost louds like an -n- or -m- right before an -s- or -th- loud. The other Theedish tungs have not lost it, other than Low Saxish somewhat. Aliken the following words:
Or-Theedish *tanþ- becomes English tooth, Old Friesish tōth (but Low Saxish Tähn, Netherlandish tand, High Theech Zahn).
Or-Theedish *anþara- becomes English other, West Friesish oar, East Friesish uur, Old Saxish āthar (but High Theech & Netherlandish ander- [þ→d]).
Or-Theedish *fimf becomes English five, West Friesish fiif, East Friesish fieuw, Netherlandish vijf, Low Saxish fiev, fief (but High Theech fünf).
Or-Theedish *samft- becomes English soft, West Friesish sêft, Low Saxish sacht, Netherlandish zacht [ft→xt] (but High Theech sanft).
Or-Theedish *gans- becomes English goose, West Friesish goes, Low Saxish Goos (but Netherlandish gans, High Theech Gans).