The term 'popped up' can be described by the crossword solutions 'arisen, ' 'appeared, ' and 'AROSE.' All three words refer to the same concept of something suddenly appearing or coming into view. 'Arisen' is a past participle verb meaning to come up or out of something, while 'appeared' is a simple past verb meaning to come into sight. Lastly, 'AROSE' is a past tense verb meaning to get up from a lying position. All three words are used to describe an object or person that has suddenly come into view.