noun
complication
kahm-plih-KAY-shun/ˌkɑːmplɪˈkeɪʃn/
An additional difficulty that makes a situation harder to manage.
The narrow doorway creates a complication for the movers carrying the sofa.

Etymology
Folding together supplied the image of an intricate intermingling. Complication later named an additional disorder arising during an illness, then more generally an added problem that makes an existing situation harder to manage.
In context
But a slight complication is that the letters are actually written in Hebrew and not Greek.
More examples
- The canceled flight creates an unexpected complication for our trip.
- Infection is a possible complication of surgery.
- We finish the repairs without any further complications.
Forms
complication · complications
complicate verb — To make something harder to manage.
complicated adjective — Difficult to understand or deal with.