"Ichthermol" is a rare word which refers to a type of wax used in photography. Its spelling is derived from the Greek words "ichthys" meaning fish and "thermos" meaning hot. Phonetically, it is pronounced as /ɪkˈθərmɒl/, with the 'ch' being pronounced as a voiceless velar fricative (like the 'ch' in Bach). The 'th' is also pronounced as a voiceless dental fricative (like the 'th' in think), with the stress on the second syllable. Despite being infrequently used, it still holds relevance in specialized fields like photography.
Mercury ichthyolate or sulphichthyolate; a blackish powder containing 24 per cent. metallic mercury.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.