vigor

UK: /ˈvɪgəʳ/ US: /ˈvɪgɚ/ ,(vig′ər)

WordReference Random House Learner's Dictionary of American English © 2025

vig•or /ˈvɪgɚ/   n. 

[uncountable]
1. active strength or force;
   intensity;
   energy:
   He pursued his new career with great vigor.
2. healthy physical or mental energy or power;
   vitality:
   He rowed with vigor.

Also,[esp. Brit.,] ˈvig•our. 

WordReference Random House Unabridged Dictionary of American English © 2025

vig•or  (vig′ər), n. 

1. active strength or force.
2. healthy physical or mental energy or power;
   vitality.
3. energetic activity;
   energy;
   intensity:
   The economic recovery has given the country a new vigor.
4. force of healthy growth in any living matter or organism, as a plant.
5. active or effective force, esp. legal validity.

Also,[esp. Brit.,] vig′our. 

• Latin vigor force, energy, equivalent. to vig(ēre) to be vigorous, thrive + -or -or¹
• Anglo-French; Middle French vigeur
• Middle English vigo(u)r 1300–50

vig′or•less, adj. 
Synonyms

• 2. drive, force, strength.

Collins Concise English Dictionary © HarperCollins Publishers::

vigour, vigor / ˈvɪɡə/ noun

1. exuberant and resilient strength of body or mind; vitality
2. substantial effective energy or force: the vigour of the tempest
3. forcefulness; intensity: the vigour of her complaints
4. the capacity for survival or strong healthy growth in a plant or animal
5. the most active period or stage of life, manhood, etc; prime

Etymology: 14th Century: from Old French vigeur, from Latin vigor activity, from vigēre to be lively