This is the 308th most frequent Indonesian word.
luka
"Wound" or "injury."
In this sentence, 'luka' is used as a noun, meaning 'wound'.
Luka di tangannya terlihat sangat dalam.
The wound on his hand appears very deep.
Here, 'luka' is metaphorically used to describe emotional hurt.
Hatinya luka karena perkataan kasar itu.
His heart is hurt because of those harsh words.
In this sentence, 'melukai' is a verb derived from 'luka', meaning 'to hurt' or 'to injure'.