Or it could be something derived from verb telconta- , similar to strides.
en.wiktionary.org - strides - Wiktionary

+Ras Alhague interesting idea!

Maybe some lateral thinking could help. I looked up the etymology of breeches and it is said to ultimately go back to a root meaning "break" as it breaks into two legs. So I thought maybe we could do something with *stanka "bifurcated, split"
http://eldamo.org/content/words/word-1984099063.html

*Þankar

+James Coish indeed. Maybe *Þankat.

Also: *Þangwa "fork"?

+Tamas Ferencz *þancat indeed works better.

+Tamas Ferencz Mentioning sangwa would cause awkward situations during meals.
eldamo.org - Eldamo : Quenya : sangwa
The Sindarin equivalent *thaew doesn't seem to clash with anything, but I hope someone would still check my neologism.

+Ras Alhague ah but then in my posh dialect speakers preserve the th and only uncouth speakers would be confused:)

Telquaima < telco + ^waima < EQ. vaima + √WAY

+Ицхак Пензев that's also a possibility. In fact, one could be used for trousers, the other for tights, for instance.