Commonly used terms:
* ஆசை (Aasai): This is the most common word for "desire" or "fondness" and can be used to express infatuation.
* மோகம் (Mogam): This word carries a stronger connotation of attraction and can be used to describe infatuation with a person.
* காதல் (Kaadhal): While this literally translates to "love", it can also be used to describe the initial stage of love, which can be similar to infatuation.
* கிறங்கல் (Kirangal): This word conveys a strong sense of longing and admiration, which can be used to express infatuation.
More nuanced terms:
* மனம் கவர்ந்தது (Manam Kavanthathu): This literally translates to "captured the heart" and can be used to express a strong infatuation.
* பேய் பிடித்தது போல் (Pei Pidiyathu Pol): This idiom means "like being possessed by a ghost" and can be used to describe an intense and obsessive infatuation.
The best choice for you will depend on the specific context and the intensity of the infatuation you want to convey.
For example, if you are talking about a fleeting infatuation, "ஆசை" might be appropriate. However, if you are talking about a more intense and obsessive infatuation, "பேய் பிடித்தது போல்" would be a better choice.