This paper aims to explore the etymology of tayngki and taynim, which are types of traditional Korean attire. In historical literature, taynim is only attested as tanim, whereas tayngki is found in several variations, with tanki being considered the most archaic form. Since both tanki and tanim share the form tan and signify a meaning associated with tying, we are led to postulate *tan- ‘to tie or be tied’ as their common root. Furthermore, another word tayngki ‘loop used to fix a sickle’s handle’ indicates that *tan- could also mean ‘to fasten or be fastened’. However, the data is insufficient to determine the transitivity of *tan-. Tanim can be analysed into *tan-+-i-+-m (nominalization suffix), with the author arguing that ‘-i-’ served as a causative suffix, separated from the well-known causative suffix -Gi-. Although tanki can be analysed into *tan-+-ki (nominalization suffix), this interpretation presents some phonological problems. To circumvent these issues, the author proposes that tanki originated from *tan- combined with a causative suffix -o-, forming *tano-～*tank-, and followed by a nominalization suffix -i.