Definition of sentinel in English:

sentinel

noun

  • 1A soldier or guard whose job is to stand and keep watch:

    ‘soldiers stood sentinel with their muskets’
    • ‘The sentinel still stood at attention directly under the lantern, not moving but to breathe.’
    • ‘She knew not whether to fear it or love it; at this moment she only wished to find someplace where she could sit, unnoticed by the sentinel who stood near the fire at the east end of the encampment.’
    • ‘A soldier high on the roof behind his machine gun watched vigilantly over the far horizon - a silent sentinel.’
    • ‘Immediately, a sentinel standing guard near the jail confronted him.’
    • ‘A lone sentinel stood in the middle of the roadway to the castle standing on the hill.’
    • ‘Take out the launchers as quickly as possible, then wipe out the remaining soldiers and sentinels with your mutant powers.’
    • ‘Men who have merited this last distinction are to be suffered to pass all guards and sentinels which officers are permitted to do.’
    • ‘Flanking the elevator on both sides stood the Shadow Lord's black-garbed sentinels, his sinister Warrior disciples.’
    • ‘There has been some speculation that Charles was assassinated, but from forensic examination of his skull it is fairly certain that an enemy sentinel caught sight of his head peering over the parapet and managed a lucky hit.’
    • ‘A group of sentinels stood to stop the elated pilots, but were gunned down with one well-placed salvo from the Omegas.’
    • ‘The sentinels who had stood watch throughout the night before watched those roadside dwellers with weary but alert eyes, should they suddenly decided to start a riot in front of the palace.’
    • ‘So say the sentinels guarding the long coastline of the country this weekend.’
    • ‘A sentinel stood on top of the wall, an easy target.’
    • ‘After walking down a short hall another door came into view; this one had only one sentinel.’
    • ‘The sentinel stood lounging by the shaft that led down into the underground labor system.’
    • ‘By the third week the men practiced guard duty, receiving instructions on walking their posts and performing interior and exterior guard duty, and learning the general and specific orders of a sentinel posted for guard duty.’
    • ‘Four silent sentinels still mounted guard at each point of the coffin but the long queues of visitors had gone.’
  • 2Medicine
    An indicator of the presence of disease:

    [as modifier] ‘the first national HIV sentinel surveillance programme in the developing world’
    • ‘Performing sentinel lymph node biopsy requires coordinated expertise between nuclear medicine physicians, pathologists, and surgeons.’
    • ‘The beetles' affinity for certain trees, like maples, poplars, willows, and elms, is significant because such attractive species may be used as sentinel trees.’
    • ‘We here present a model of field study, based on the use of sentinel species, that we are currently applying to risk assessment in the area around a focus of pollution.’
    • ‘Surveillance for West Nile is also conducted by testing pools of mosquitoes and flocks of sentinel chickens.’
    • ‘Amphibians are regarded as sentinel vertebrates in the current drama of global extinctions.’

verb

[WITH OBJECT]
  • Station a soldier or guard by (a place) to keep watch:

    ‘a wide course had been roped off and sentinelled with police’

Origin

Late 16th century: from French sentinelle, from Italian sentinella, of unknown origin.

Pronunciation:

sentinel

/ˈsɛntɪn(ə)l/