practical question (problem)

sharp rise; sudden rise / (of aircraft) ascent at a steep angle

to rise sharply; to rise suddenly / (of aircraft) to ascend at a steep angle

(of aircraft) nosedive; descent at a steep angle; plunge

(of aircraft) to nosedive; to descend at a steep angle; to plunge

steep angle

(computing, Internet) Address Resolution Protocol, ARP

(idiomatic) to have grown tense (of a situation); to have become critical (and to be on the verge of a major upheaval)

(computing, Internet) Reverse Address Resolution Protocol, RARP

(computer science) steepest descent method