From Longman Dictionary of Contemporary Englishdisconcertdis‧con‧cert /ˌdɪskənˈsɜːt $ -ɜːrt/ verb [transitive] CONFUSEDWORRIEDto make someone feel slightly confused, embarrassed, or worried —disconcerted adjective a disconcerted look→ See Verb table
Examples from the Corpus
disconcert• She was not as disconcerted as she had expected to be.• Sometimes, she thought she disconcerted Hawk with her love, but he kept apace with her.• Nothing was known to disconcert him, certainly not the death of a man he had disliked.• This new benignity and tolerance a little disconcerted him.Origin disconcert (1600-1700) Old French desconcerter, from concerter “to bring into agreement” 