pressurethe continuous physical push exerted on a surface per unit area by a fluid or gasAtmospheric pressure decreases with altitude, which is why it is harder to breathe on mountaintops.NoteAtmospheric pressure decreases with altitude, which is why it is harder to breathe on mountaintops.Elon.io is an online learning platformWe have an entire course teaching TOEFL Academic Vocabulary grammar and vocabulary.Start learning TOEFL Academic Vocabulary now