The phrase "sprung in" refers to something or someone that suddenly appears or arrives, often unexpectedly or without warning. There are several synonyms that can be used in place of "sprung in," including "popped up," "surprised," "emerged," "materialized," "appeared," and "arrived abruptly." These synonyms all convey a sense of suddenness or surprise, emphasizing the unexpected nature of the event or object that has "sprung in." Whether it's a surprise visitor, an unexpected idea, or a sudden change in circumstance, the phrase "sprung in" and its synonyms capture the sense of unpredictability and surprise that can sometimes catch us off guard.