Try "Tser" or "Tsaer" from the word tsunami [tsoo-nah-mee], or "Ser" or "Saer", if you are using a common mispronunciation of tsunami as the base word to support that, or finally "Teer" or "Taer", using the first syllable of one of the common pronunciation of the word tsetse. [tset-see, tet-, tsee-tsee, tee-]
My personal choice would probably be "Tsaer".
Hope That Helps,
Flynn