In Stargate Atlantis, they creatures called Iratus bugs (what the Wraith evolved or mutated from), how do you pronounce 'Iratus', is it like I-RAT-US, E-RAT-US or E-RATE-US ? Because I've heard it pronounced all three.
I'm not able to dig through actual SGA episodes at the moment to find how it's pronounced in the show, however:
- This propworx video selling an Iratus bug prop pronounces it eye-RAY-tus
- Wiktionary's page on "iratus"1 pronounces it ee-RAH-toos; that said, Latin is a dead language, so defining "proper pronunciation" for Latin words is difficult
- "Iratus" is an actual Latin word, the perfect passive participle of īrascor ("be angry, be in a rage").
In the SG universes, it can often be difficult to arrive at a single pronunciation for alien terminologies. The iratus bug is just one example. If you follow the series closely, you will notice that the following important terms are all pronounced differently by different characters quite frequently:
- Goa'uld > GEWLD, goo-UH-EWLD, GOH-uh-EWLD, GO-uh-old
- Jaffa > JUH-fah, JAWF-uh, JAFF-uh
- Tok'ra > TOKE-RAH, TOKE-ruh
This could be explained by the different dialects and accents of the characters speaking the names. Additionally, it could be a matter of seeing the word before hearing it (such as reading a mission report.) When this happens, you tend to pronounce the word as you guessed it would be pronounced when you saw it.
So, as it seems to be for the SG characters (or the actors), the pronunciation would be the one the speaker is most comfortable with.
In episode 8 of season 2 (Conversion) Doctor Beckett refers to it as an "air-ay-tuss". In the same episode, Weir calls it an "air-at-tuss" and and McCay refers to it as an "ir-rat-uss".
The pronunciation on the show seems relatively flexible but as other posters have noted, the word iratus itself is a real world Latin word that means 'angry' and would be correctly pronounced (in the original Latin) as "ere-aah-tuss".
A pronunication file can be found here
It's always problematic for native speakers of English to even approach the "original" phonetics of Latin or Greek words. Not that it is easy for speakers of other languages but most of them at least come somewhat near to the "original". That's why one can often count on a laugh among f.e. Poles, Italians, Germans etc when they hear one of those anglifications of latin and greek words.