Definition of treacherous in English:



  • 1Guilty of or involving betrayal or deception.

    ‘a treacherous Gestapo agent’
    ‘memory is particularly treacherous’
    • ‘He's deposed by a treacherous underling, winds up on the street, and is taken in by a tough noodle vendor with messed up teeth.’
    • ‘The fate of the farm animals was so grim, the pigs so mean and mendacious and treacherous, the sheep so stupid.’
    • ‘Philip found that following the logic of these conspiracy theories was deeply treacherous and disorienting.’
    • ‘Josh had been promoted recently because of a treacherous betrayal by the old Number Four.’
    • ‘And behind that grinning face lay a treacherous, poisonous personality.’
    • ‘Is it treacherous to say I hope we lose every game in the World Cup?’
    • ‘Rather than admit the great man is in fact a great flop, they label these dedicated economic soldiers as treacherous.’
    • ‘Gone are interesting characters like the greedy and treacherous aide, and that marvelous biplane.’
    • ‘But David says we should not be too confident that those people whose heads looked down from the bar were truly treacherous.’
    • ‘The left on Auckland City's council have become self-indulgent and treacherous to each other.’
    • ‘For example, he embodied animals that were weak, cowardly, false, and treacherous.’
    • ‘I realise that he likes the tortured martyr parts in which he valiantly combats the treacherous world that seeks to subdue him.’
    • ‘They are a treacherous people who violate oaths and covenants.’
    • ‘When the robber opened the note and read what the king had written, he realized the king had devised a treacherous plan.’
    • ‘They are not deceitful or treacherous in their conduct and are faithful to their oaths and promises.’
    • ‘The earliest documented ballads feature Robin Hood as lusty, treacherous and violent.’
    • ‘He proved a selfish, egocentric, ungrateful, and treacherous recipient of Noble's many kindnesses.’
    • ‘They are not anywhere near as treacherous as crack addicts or alcoholics for that matter.’
    traitorous, disloyal, perfidious, faithless, unfaithful, duplicitous, false-hearted, deceitful, false, untrue, back-stabbing, double-crossing, double-dealing, two-faced, janus-faced, untrustworthy, unreliable, undependable, fickle
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  • 2(of ground, water, conditions, etc.) presenting hidden or unpredictable dangers.

    ‘a holidaymaker was swept away by treacherous currents’
    • ‘It can be very treacherous and can give way at any time.’
    • ‘We made it to the top, but coming down was more treacherous.’
    • ‘On that day Couples' tee-shot to Golden Bell, the treacherous par three, clung miraculously to the bank of the Creek.’
    • ‘The road in Tunduffe has now gained such a high level of points that Gardai declare it treacherous and a serious accident risk.’
    • ‘I thought that in my years as a reporter I had navigated some fairly treacherous terrain.’
    • ‘I dragged myself up, hanging on to the treacherous railing, and lumbered up the stairs, bruised all over.’
    • ‘He parallels the paths of two very different figures, each coming of age and choosing a path in life during a treacherous time.’
    • ‘A grieving family has pleaded for action to be taken on a treacherous bend that this week claimed the life of their mother.’
    • ‘Weather conditions in the area at the time of the incident were described as treacherous by local emergency services.’
    • ‘The women worked the wind-swept fields while the men worked the quarries and manned fishing boats in famously treacherous seas.’
    • ‘It resembles a treacherous dungeon, which is strange because one wall is entirely windows.’
    • ‘The descent is worse, in parts a sheer drop on a thin track almost hidden by heather with treacherous rocks and holes ready to trip up even the most nimble feet.’
    • ‘The earth is rich and dead, and offers treacherous footing.’
    • ‘If the Marina is known for its strong undercurrents, the sand on Elliots Beach is treacherous as it keeps shifting.’
    • ‘The views open out to the north-east, across the treacherous Pentland Firth to Orkney, as you reach Portskerra pier.’
    • ‘My inertia in not pushing it backwards into a safe zone is as guilty for the shattered glass as the treacherous wind.’
    • ‘Many side roads were treacherous and remained so till Tuesday and several minor accidents occurred as a result.’
    • ‘As the treacherous winter months lie ahead, let's not wait for more alarming statistics to bring us to our senses.’
    • ‘The Garavogue is a fast-flowing treacherous river and we can do without those vandals who steal the ring buoys.’
    • ‘Some 500,000 vessels a year pass through the treacherous, narrow Bosporus and Dardanelles straits.’
    dangerous, hazardous, perilous, unsafe, precarious, risky, deceptive, unreliable, undependable, unstable
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Middle English (in treacherous): from Old French trecherous, from trecheor a cheat, from trechier to cheat.