[ sɪ'nɪərɪsɪs ]
■ noun ( plural synereses -si:z )
1》 the contraction of two vowels into a diphthong or single vowel.
2》 Chemistry the contraction of a gel accompanied by the separating out of liquid.
Origin
C16: via late L. from Gk sunairesis , based on sun- 'together' + hairein 'take'.