David Bowie’s son, Duncan Jones, weighed in on Lady Gaga’s colorful tribute to his late father at the 58th Grammy Awards on Monday night. The Moon director shared his thoughts on the spectacle by tweeting the Oxford English Dictionary definition of the word “gaga.” “‘Overexcited or irrational, typically as a result of infatuation or excessive enthusiasm; mentally confused.’ Damn it! What IS that word?” he wrote.