We received a letter expressing the hospital's sincereapologies.
Times, Sunday Times (2006)
We offer our sincereapologies for this oversight on our part.
Times, Sunday Times (2011)
Seeoffer an apology
Definition of 'sincere'
sincere
(sɪnsɪəʳ)Explore 'sincere' in the dictionary
adjective
If you say that someone is sincere, you approve of them because they really mean the things they say. You can also describe someone's behaviour and beliefs as sincere.