isinglass
/ˈʌɪzɪŋˌɡlɑːs
/noun [mass noun]
1A kind of gelatin obtained from fish, especially sturgeon, and used in making jellies, glue, etc. and for fining real ale.The animal kingdom was represented by gelatin in the form of meat stock; isinglass; and hartshorn....
- Antonin poured the thickening isinglass alternately into the fruit juice and the almond milk.
- Sometimes the wood surface was prepared with a coating of gesso or isinglass diluted in water with a little white pigment added.
2chiefly US Mica or a similar material in thin transparent sheets.
Origin
Mid 16th century: alteration (by association with glass) of obsolete Dutch huysenblas 'sturgeon's bladder', from huysen 'sturgeon' + blas 'bladder'.