As in two words - “kilo” and “metre”.
Not Kil-lom-iter.
Both. Because my parents said it one way, and more official channels said it the other, I can’t remember which.
As it’s a measure of distance and not a measurement device, the formally correct pronunciation should be “KILL-o-mee-ter”. Like centimetre, and millimetre, and not like thermometer or odometer.
“kill-AH-mi-ter” for me. I always thought that was a more European pronunciation, or at least British.
The Thais say “gi-lo-MET.”