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Hello,

I suppose 'to keep a lookout for' is a common collocation. But how about the phrase 'to keep a vigilance for'?

Is the word 'vigilance' acceptable in the sentences below? Thank you for your answers.

The horse kept a careful LOOKOUT for predators while it grazed.

The horse kept a careful VIGILANCE for predators while it grazed.

The horse could keep a constant vigilance for predators while it grazed.
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To me, 'vigilant' is a somewhat out-dated word (Biblical, old west 'vigilantes').

Your use is not incorrect, however.

It will be interesting to see what other native speakers have to say.
Comments  
successorThe horse kept a careful VIGILANCE for predators while it grazed.

The horse could keep a constant vigilance for predators while it grazed.
I've never heard "vigilance" used like this. You probably mean "careful vigil".