A beaker
A beaker was a type of container used by scientists to hold liquids. It had a spout that allowed for easy pouring.
On Miri in 2266, Spock warned that, without being able to access the USS Enterprise's computers, he and the other members of a landing party from the starship couldn't determine whether a potential vaccine against a particular deadly virus, which had been created due to a life prolongation project on that planet, was safe or a "beaker full of death." (TOS: "Miri")
In 2377, The Doctor irately blamed Tom Paris for the fact that he was putting into beakers in sickbay instead of on the greens at Saint Andrews. (VOY: "Drive")