Based on the clue "I call dibs," "thisismine" appears to be a phrase or expression indicating possession. It suggests that the speaker is stating their claim or ownership of something. A possible definition could be: asserting the right to possess or claim something as one's own.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: "I call dibs". Explanations are generated by AI and may be inaccurate.