isinglass
noun
isin·glass ˈī-zᵊn-ˌglas 
ˈī-ziŋ-
1
: a semitransparent whitish very pure gelatin prepared from the air bladders of fishes (such as sturgeons) and used especially as a clarifying agent and in jellies and glue
2
: mica especially when in thin transparent sheets
especially : muscovite sense 2
Example Sentences
Recent Examples on the Web Occasionally, bottles are fined, or clarified, with animal products like egg whites, milk casein or isinglass, which comes from fish. 
New York Times, 15 Jan. 2021 The paper was made of cloth, sometimes silk and isinglass, which is somewhat see-through and made from fish air bladders. Jonah Estess, The Conversation, 29 Aug. 2019 Langton said Norwegians have a long history of woodcarving as a way to express themselves during the long winters that kept them in dark cabins, many of which did not have windows until the invention of isinglass in the 1600s. Brian E. Clark, Milwaukee Journal Sentinel, 22 Dec. 2017 The fish were utilized for caviar, isinglass and even as fuel for steamships, according to reports. Paul A. Smith, Milwaukee Journal Sentinel, 14 Oct. 2017
New York Times, 15 Jan. 2021 The paper was made of cloth, sometimes silk and isinglass, which is somewhat see-through and made from fish air bladders. Jonah Estess, The Conversation, 29 Aug. 2019 Langton said Norwegians have a long history of woodcarving as a way to express themselves during the long winters that kept them in dark cabins, many of which did not have windows until the invention of isinglass in the 1600s. Brian E. Clark, Milwaukee Journal Sentinel, 22 Dec. 2017 The fish were utilized for caviar, isinglass and even as fuel for steamships, according to reports. Paul A. Smith, Milwaukee Journal Sentinel, 14 Oct. 2017 Word History
Etymology
probably by folk etymology from obsolete Dutch huizenblas, from Middle Dutch huusblase, from huus sturgeon + blase bladder
First Known Use
1535, in the meaning defined at sense 1
Medical Definition
isinglass
noun
isin·glass ˈīz-ᵊn-ˌglas ˈī-ziŋ-
ˈī-ziŋ- 1
: a semitransparent whitish very pure gelatin prepared from the air bladders of fishes (as sturgeons) and used especially as a clarifying agent and in jellies and glue
called also ichthyocolla
2
: mica