From Longman Dictionary of Contemporary Englishconspiratorialcon‧spi‧ra‧to‧ri‧al /kənˌspɪrəˈtɔːriəl/ adjective 1 SECRETa conspiratorial expression, voice, or manner suggests you are sharing a secret with someone His voice became low and conspiratorial. Pat whispered to Maggie in a conspiratorial tone.conspiratorial whisper/smile/wink etc Britta gave him a conspiratorial smile.2 PLANrelating to a conspiracy —conspiratorially adverb
Examples from the Corpus
conspiratorial• I don't want to make the novel sound wacky, let alone conspiratorial.• The answers range from the technical to the vaguely conspiratorial.• They were worn with one end thrown across the shoulder high under the chin, giving the wearer a conspiratorial air.• The behaviour of firms need not be conspiratorial in the legal sense.• Nick and I shot a conspiratorial look at each other: this time we would refuse to fight.• A friendly, conspiratorial smile for Bernice, a sympathetic glance for Defries, a half-angry, half-amused growl for Daak.• Britta gave him a curiously conspiratorial smile.conspiratorial whisper/smile/wink etc• Britta gave him a curiously conspiratorial smile.• The waiter gives us a conspiratorial wink.• A friendly, conspiratorial smile for Bernice, a sympathetic glance for Defries, a half-angry, half-amused growl for Daak. 