Dictionary.com
Thesaurus.com

thioaldehyde

American  
[thahy-oh-al-duh-hahyd] / ˌθaɪ oʊˈæl dəˌhaɪd /

noun

Chemistry.
  1. any of a class of compounds formed by the action of hydrogen sulfide on aldehydes, and regarded as aldehydes with the oxygen replaced by sulfur.


Etymology

Origin of thioaldehyde

thio- + aldehyde