The Ruling on Men Shortening their Eyebrows
Question :
If the hair of the eyebrows becomes thick, is it permissible to shorten it a little, without intending to imitate women, or change Allah's creation?
Answer:
I do not consider it allowed to pluck the eyebrows, or to trim them or shave them; this is because Allah, the Most High caused them to grow for the purpose of beauty and decoration, and they protect and preserve the eyes. Therefore, their removal by a man or a woman is changing the creation of Allah, but because it is mostly women who do so, the threat of the curse was made upon them.
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 1 Page 393