Wiktionary
sippy cup
n. A spill-proof cup for toddlers
Wikipedia
Sippy cup
The sippy cup is a spill-proof drinking cup designed for toddlers. It works by way of surface tension that prevents liquid from being spilled even when the cup is upended. The critical element is the sippy top being firmly in place on top of the cup, preventing spills.
The modern Sipster spill-proof sippy cup was invented by Richard Belanger, who licensed the design to Playtex.
Sippy Cup (Melanie Martinez song)
"Sippy Cup" is a song by American recording artist Melanie Martinez as the third single from her debut album, Cry Baby. A music video was released July 31, 2015.