Bonnie Blue Butler had the situation come up at work where they had to find a good way to translate the English word "guarantee" into Hindi. This was a real-world marketing problem, and eventually they decided to go with "gaaranti", the word "guarantee" transliterated into Hindi.

I discussed it with her and I think it was the right thing to do. Now, this may be a pedantic point, but I must assure you that Hindi does not lack for an equivalent to the word "guarantee". Noting that Hindi owes its roots to both Sanskrit as well as the Middle Eastern languages, there are two separate vocabularies and therefore there are at least two different ways to express the word 'guarantee' in Hindi. One equivalent is the word "zamaanat". Another equivalent is the Sanskrit-nisht word "prathyabhoot". The problem for the marketers, of course, is that neither set of words may be particularly accessible. Given the complex linguistic situation in South Asia, the transliterated English word "guarantee" is likely the best bet.