From Old Norse teðja, from Proto-Germanic *tadjaną (“to strew, scatter”), from Proto-Indo-European *dāy- (“to divide, split, part, separate”). Related to tað (“[horse or sheep] dung”). More at tath.
teðja (weak verb, third-person singular past indicative taddi, supine tatt)
- (transitive) to strew manure on, to fertilize with manure; to manure, to dung
- (intransitive) to defecate (of animals, especially horses)