complicate
/ˈkɒmplɪkeɪt/verb
with obj.
1- make (something) more difficult or confusing by causing it to be more complex使复杂化; 使困难（或混乱）：
increased choice will complicate matters for the consumer
对消费者来说, 选择增多将使他们面临更复杂的情况。
as adj. complicating a complicating factor.使情况复杂化的因素。
1.1
- Medicine introduce complications in (an existing condition)【医】引起并发症：
smoking may complicate pregnancy
怀孕时吸烟可能引起并发症
as adj. complicating patients with complicating biliary calculi.易引起并发症的胆结石病患者。
词源
early 17th cent. （in the sense 'combine， entangle， intertwine'）： from Latin complicat- 'folded together'， from the verb complicare, from com- 'together'+plicare 'to fold'.