How to add Tag to Text block/Code block to make more words searchable.

Hi!
ATM my search doesn't work properly, so I can't try out different things yet (it's been reported and worked on). 
My webpage is written in English.
What I want is to somehow give my text blocks tags, I want people on my webpage (not published yet) to be able to search for a subject, but with a word for the subject from their own language, but still get the English result. English is not my first language and I know first hand how frustrating it can be to know the word for something in my own language, but not in English, spending too much time trying and hoping to figure it out.
Does anyone of you know if it is possible to make sort of tags in text/code block or if this wish for my search block results is even possible without a lot of coding?. The simpler solution the better.
Example: Bomull is the Swedish/Norwegian word for Cotton, so if I went to the search block on my webpage and typed in Bomull, the page about Cotton would show up in the search results. Of course you still need to know English, but not know all English technical words about a subject .
All tips and help highly appreciated! 

Chanti