vigil – (noun) the act of keeping awake at times when sleep is customary; also : a period of wakefulness

i found this definition at https://www.merriam-webster.com/dictionary/vigil

I found this word in the Text the hunger artist.

Of course there were people who argued that this breakfast was an unfair attempt to bribe the watchers, but that was going rather too far, and when they were invited to take on a night’s vigil without a breakfast, merely for the sake of the cause, they made themselves scarce, although they stuck stubbornly to their suspicions.“

Knowing this definition helps understand what they are talking about because a nights vigil could have been anything but now I know that it’s a sleepless time period