“light (weight)” in Japanese is 軽, read kei, karu, karo (けい, かる, かろ). It is a Grade 3 Kyōiku kanji, taught in year 3 of Japanese elementary school, and appears in words such as 軽い (light).
What does 軽 mean?
このかばんは軽い。
Same sound, different character — the classic trap. Compare them side by side: