1. to not appreciate sb/sth, to expect sth to continue (without change)
don't take it for granted, it could be gone tomorrow!
If you take someone or something 'for granted' you fail to properly appreciate or value it because you assume they will always be there. "I have been putting in a lot of extra work that I feel has been taken for granted."
2. assume something is true without checking it, accept as fact
a lot of people take for granted what they see on the News/Internet
If you take a fact or information for granted you assume it is true without checking otherwise. "If we take for granted that these figures are correct, we are in a lot of trouble." Similar in meaning to 'if we take as fact' and 'if we assume'.