noun · complicated problems or difficult situations that are hard to resolve or handle

他在修理精密仪器方面经验丰富，专门解决各类技术上的疑难杂症。

noun · dubious or hard-to-treat medical conditions that are difficult to diagnose or cure

许多病人慕名而来，请这位老中医诊治各种疑难杂症。