kilolitre, (kokuji)
竏 is a Japanese-made kokuji that represents a unit of volume: one kilolitre. It has no other common meanings.
竏 is a modern Japanese kokuji created by combining 立 (standing, here likely used phonetically for 'kilo') and 千 (thousand) to represent a kilolitre (1000 litres).
A thousand (千) litres standing (立) together make one kilolitre: 竏.
For キロリットル, the reading is simply the Japanese pronunciation of 'kilolitre'. Think of a kilo (キロ) of litres (リットル) standing in a thousand-litre tank.
—