Litre
From Tardis Wiki, the free Doctor Who reference
A litre was a measurement used to measure liquids used by humans and Time Lords.
The Tenth Doctor once used many litres of water to drown the Racnoss. (TV: The Runaway Bride)
The First Doctor once had to give two litres of his TL-positive blood to Xing Surgeon, Aldridge for a surgery. (PROSE: A Big Hand for the Doctor)