Origin of these words in Cornish and Welsh

Does anybody have any idea of the origins of the words 'pychya' (to stab) and 'Troellya' (to turn) in Cornish and the word 'troi' (to turn) in Welsh?
I am having a hard time ascertaining the etymologies of these words as etymological information regarding these language is wanting.

Cornish has now become almost extinct in England so it is hard to find etymologies for their words. I've been trying to find the etymology but I've not been successful.

Creo que "pychya" viene de la palabra española "pinche". Es una palabra bonita que se puede usar de muchas maneras para expresar una plétora de sentimientos e ideas profundas.

En todo caso sería de "picha".

Franco, por lo visto hablas/escribes muchos idiomas... no quisiera parecer demasiado curioso pero me encantaria saber de donde eres?

Nací en una base argentina de la Antártida.

Thanks for your help.

"pychya' (to stab)"

— obviously related to Fr. <piquer> (= "to stab", "to pierce"), which is itself of Celtic origin.
See also Eng. <pike> ("spear"), from Fr. <pique>, also from Celtic origin (or Germanic perhaps).

pike (2)
"weapon," c.1511, from M.Fr. pique "a spear, pikeman," from piquer "to pick, prick, pierce," from O.Fr. pic "sharp point or spike," perhaps ult. from a Gmc. or Celtic source.

http://www.etymonline.com/index.php?search=Pick&searchmode=none

Interesting, in Spanish there is a similar word with similar meaning too:
"Picar", which means to make a wound with a pointed weapon. According to RAE this word is related to "pico" (pointed weapon"). RAE says that "Pico" derives from Celtolatin

Hence the well-known "picadors" in bullfights.

According to Gerlyver Kernewek Kemmyn 'pychya' is a borrowing from Middle English piche. Piche is listed in the Oxford English as an obsolete form of pike or pitch. The same source also states that 'troellya' is derived from the Old French word 'trouill' meaning a spool which was
also borrowed into Welsh and Breton as 'troi' and 'troiñ' respectively.