[vig.i.lant] adj [ME, fr. MF, fr. L vigilant-, vigilans, fr. prp. of vigilare to keep watch, stay awake, fr. vigil awake] (15c): alertly watchful esp. to avoid danger syn see watchful -- vig.i.lant.ly adv
VIGILANT
Meaning of VIGILANT in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012