From Longman Dictionary of Contemporary Englishsentinelsen‧ti‧nel /ˈsentɪnəl/ noun [countable] old-fashioned PMa sentry
Examples from the Corpus
sentinel• In its normal form the gene, called p53, appears to act as a sentinel against excessive cell growth.• Large dark pines stood like sentinels guarding the sweep of wintry garden.• Stumpy Martello towers, built to repel Napoleon, stand sentinel on the shoreline.• Owl Lodge has fine glowing orange owl standing sentinel above the parking lot.• Was it some supernatural sentinel of the Scarabae?• But all was still save the measured tread of the sentinel and the gentle whispers of the genial night breeze.• The sentinels of the media swarmed the fracas.Origin sentinel (1500-1600) French sentinelle, from Old Italian sentinella, from sentina “keeping watch”, from sentire, from Latin; → SENTIENT 