Desoto refers to DeSoto, which is a brand of automobiles. The clue "Explorer from 63-Across" is suggesting that DeSoto may be associated with the exploration of a specific place or a person associated with exploration. However, without knowledge of what 63-Across refers to, it is difficult to provide a specific definition.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Explorer from 63-Across. Explanations are generated by AI and may be inaccurate.