It appears to me that ...

It's not a word, it consists of the two seperate particles か (question, doubt, "or") and と (quotation particle). So you could translate it like It's a checkmate, hm? That's what it seems to be.

I‘m sorry.I am not very good at Englishi. I donnot think かと is a Japanese word.It just means "doubt". 「チェックメイトかと思われた」の「かと」は分けて考える必要だと思います。 まず、「か」は疑問の意味を表します。 「と」には深い意味が無いですが、「思う」と一緒によく使われます。