What does "underinflated" mean?

simple past and past participle of underinflate

How do you pronounce "underinflated"?

Pronounced //ˌʌndəɹɪnˈfleɪtɪd//.

/ˌʌndəɹɪnˈfleɪtɪd/ verb

verb ·Rare ·Advanced level

Verb

"The tyre is a bit underinflated."