Anyone interested in German phonetics should click here for my PowerPoint letter on the phonemes of German or here for the page on German phonetics on my German Dialects linklist. This pronunciation guide is subdivided into sections on German consonants, German vowels and pronunciation exercises.
The name Gillian is of Latin and English origin. The meaning of Gillian is downy-bearded, soft haired, implying youthful. Gillian is generally used as a girl's name. It consists of 7 letters and 3 syllables and is pronounced Gi-lli-an.
However, the entry for gill gives a pronunciation like fish gill or Vince Gill, with Jill as a secondary pronunciation, and the word comes from the given name Gillian. I suppose that means Gillian is most likely pronounced like fish gill, but it is sometimes pronounced Jillian.