This word has so many alternative pronunciations that about the only thing that can be guaranteed is that it will contain a k. The first vowel can be any of iː ɪ ə. The second vowel can be any of ɒ ɔː ʌ ə. The final consonant can be s or z. The first syllable can disappear altogether. Some speakers use a pronunciation which contains ə in the second syllable even though it is stressed. In very relaxed speech (especially if the next word begins with a vowel) all the vowels in the word may disappear and we are left with kz or ks.