This is the 424th most frequent Hungarian word.
rajta
"Rajta" means "on it" or "on" in English.
Here, 'rajta' means 'on it', referring to the location of the coat.
Rajta van a kabátom.
My coat is on it.
Here, 'rajta' indicates active participation in the task, metaphorically being 'on' it.
Rajta vagyok a feladaton.
I am working on the task.
Here, 'rajta' is used as an interjection to encourage action, meaning 'come on' or 'let's go'.