rearing one's head

Verb

rear one's head (third-person singular simple present rears one's head, present participle rearing one's head, simple past and past participle reared one's head)

1. (literally) To raise one's head.

   Synonyms:

   raise one's head

2. (idiomatic) To appear and cause problems or stress, especially at an inopportune time (said of something or [rare] someone that is undesirable or unwelcome).
   • One problem that reared its head in 1983 would prove more difficult to solve, with the heat that summer leading to a number of engine failures.2021 October 6, Greg Morse, “A need for speed and the drive for 125”, in RAIL, number 941, page 53