שָׂמֵחַ • (saméakh)
Note the patakh gnuva at the end of the word, making the sound akh, rather than kha, as would be typical. This happens when ח (or apparently with ע, or הּ) is at the end of a word w/ a patakh. As far as I know this is not terribly common.
Another notable example of this is Noah - נֹחַ (Noakh)