i·so·cy·a·nate 
(ī′sō-sīə-nāt′, -nət)
(ī′sō-sīə-nāt′, -nət)n.
1. A chemical group, NCO.
2. A salt, ester, or anion of isocyanic acid.
3. Any of various compounds that contain an isocyanate group, NCO. Isocyanates are used mainly in production of polyurethane and can cause respiratory disorders, especially asthma, if inhaled.
[ISOCYAN(IC ACID) + -ATE.]