IPA: /ˌʌndərɪnˈfleɪʃən/
KK: /ʌndərɪnˈfleɪʃən/
A situation where the inflation of something, like vehicle tires, is not sufficient or is below the recommended level.
The car's performance suffered due to underinflation of the tires.
Underinflation is formed from "under-" (meaning below or insufficiently) and "inflation" (from Latin "inflatio", meaning to blow up or swell). The term describes a state where something, typically a tire or a ball, is not sufficiently inflated or filled with air.
Think of 'under-' meaning below or insufficient, and 'inflation' meaning to swell or blow up. This helps you remember that underinflation refers to something that is not sufficiently filled with air.