whoosis

/ˈwuːzɪs/
noun
  1. A word used when you cannot remember or do not know the name of a person or thing; a whatchamacallit.
    • I need to talk to the whoosis in charge of scheduling.
    • Can you hand me that whoosis on the shelf?
    • She pointed to a small gadget and said, 'This whoosis opens the bottle.'