Mahir is an Arabic name for boys that means "skilled", "talented", "accomplished", "adept", "smart". It is not a Quranic name but since the meaning is good Muslims can use it. It is pronounced as (MA)ster + (HI)ll + p(R)ay. Mahir can also be spelled as Maahir, Maher.
Mahir also has a girl-name version, which is Mahira. It has the same meaning, is non-Quranic, and is pronounced as (MA)ster + (HI)ll + (RU). Mahira can also be spelled as Mahirah, Mahera, Maherah, Maahira, Maahirah.
For both names the stress is on the beginning, the Ma- part.