What is actually meaning of "Touchwood"?

"Knock on wood" is a term from ancient Indo-Europeans who because they believed spirits lived in the trees that knocking on wood would evoke a blessing.

It derives from the pagan belief that malevolent spirits inhabited wood, and that if you expressed a hope for the future you should touch, or knock on wood to prevent the spirits from hearing and presumably preventing your hopes from coming true.

It's a saying if you are saying something and you dont want anything bad to happen you say touch wood

long ago, before Christianity came to europe, the predomiant belifes, were a bit like Hindu form, Many gods/spirits inhabiting all things.
for them, wood contained "faires" or "elves" that knew a lot, and saw all. to touch or knock on wood was to alert them that you KNW they see it all, and were "just kidding"

Supposedly you're calling on the spirits that live in the wood to keep harm from befalling you.

I'm but I know about torchwood on Doctor Who

I believe it’s the anagram of Doctor who

Like a”good luck charm”☺️