Based on the search results, the answer to the question "what a multitasker might kill" is BIRDBIRDSTONE. This answer is related to a crossword puzzle clue from The New York Times Crossword. It is important to note that this answer is specific to the crossword puzzle and does not have any real-world implications.

It is worth mentioning that multitasking can have negative effects on productivity and learning. Multitasking can lead to stress and errors in work, and it is not an effective way to get things done. Instead of multitasking, the human brain performs a function called "task switching," which can also lead to a decrease in productivity. Therefore, it is recommended to focus on one task at a time to maximize productivity and efficiency.