It is a word used to describe someone with exceptional intellectual ability, creativity, or talent in a specific field. It's often used to describe people who are considered to be prodigies or exceptionally gifted.
Here are some examples of how "tensai" is used:
* "He's a tensai at math." (彼は数学の天才です。)
* "She's a tensai musician." (彼女は天才的な音楽家です。)
* "That painting is the work of a tensai." (あの絵は天才の作です。)
It's important to note that "tensai" is a very strong word, and it's not used lightly. It's reserved for people who are truly exceptional in their field.