General synonyms:
* Passion: A strong feeling of enthusiasm or excitement for something.
* Fervor: Intense and passionate feeling.
* Zeal: Great energy or enthusiasm in pursuit of a cause or objective.
* Intensity: Great strength or forcefulness.
* Vigor: Physical strength and energy.
* Enthusiasm: A feeling of intense excitement and eagerness.
Synonyms emphasizing love or romance:
* Passion: A strong feeling of love or sexual desire.
* Love: A deep feeling of affection and care.
* Desire: A strong feeling of wanting something.
* Yearning: A deep longing for something.
* Infatuation: A strong feeling of love or admiration for someone.
Synonyms emphasizing intensity:
* Fire: A strong, intense feeling or emotion.
* Heat: A feeling of intense passion or excitement.
* Fervency: Great intensity of feeling or conviction.
* Eagerness: A strong desire or interest in something.
The best synonym to use will depend on the specific context of your writing. Consider the nuance of the word "ardor" and choose a synonym that most accurately reflects its meaning in your sentence.