Crossword Genius

Does it limit the writer's movements? (3)

Ross

I believe the answer is:

pen

I'm a little stuck... Click here to teach me more about this clue!

'limit the writer's movements?' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for pen that I've seen before include "Coop" , "Small enclosure" , "Confine the writer" , "Prison" , "record" .)

I've seen this clue in The Irish News.
Want a hint initially instead of a full solution? Install my app