vigour: [14] Latin vigēre meant ‘be lively, flourish’ (it came from the Indo-European base *wog-, *weg- ‘be lively or active’, which also produced English vigil, wake and watch). From it was derived the noun vigor ‘liveliness’, which passed into English via Old French vigour. From the same source come vigorous [14] and invigorate [17]. => invigorate, vigil
