CO-see-mah would be my first guess. But I could just as easily be persuaded to say co-SEE-ma.
Totally usable.
I find
Faith pretty much uninteresting and unmemorable in the middle, but it's not like it sounds bad.
Cosima Plum
Cosima FayeCosima JuneCosima JuniaCosima LiseCosima Fern
Three boys nappin', one mama namenerdin'
To peruse my top 100ish names:
http://www.behindthename.com/pnl/82589
He is becoming greater, I am becoming less
Bits of the journey here:
http://jodifriesen.blogspot.ca/And some family cuteness here:
https://www.flickr.com/photos/41705228@N08/