complication

noun

com·​pli·​ca·​tion ˌkäm-plə-ˈkā-shən 

1

a

: complexity, intricacy

especially : a situation or a detail of character complicating the main thread of a plot

b

: a making difficult, involved, or intricate

c

: a complex or intricate feature or element

d

: a difficult factor or issue often appearing unexpectedly and changing existing plans, methods, or attitudes

2

: a secondary disease or condition developing in the course of a primary disease or condition

Synonyms of complication

• difficulty
• complexity

Examples of complication in a Sentence

The negotiations stalled when complications arose.

Pneumonia is a common complication of AIDS.

She experienced complications during her pregnancy.

The patient died of complications from surgery.

Recent Examples on the Web

While some live with lifelong complications, others need a full heart transplant that requires them to take medication for the rest of their lives, according to the Centers for Disease Control and Prevention. — Lauren Mascarenhas, CNN Money, 20 Aug. 2026

Severe coronavirus infections can lead to significant health complications such as blood clots, kidney injury or heart issues, according to the Mayo Clinic. — Hali Smith, Idaho Statesman, 19 Aug. 2026

Logistical complications meant Hurzeler’s plans to watch some of Ancelotti’s training sessions with Brazil had to be abandoned. — Andy Naylor, New York Times, 19 Aug. 2026

Clinical trials are underway, but patients currently rely largely on supportive care, such as fluids and treatment of symptoms and complications. — ABC News, 19 Aug. 2026

Word History

Etymology

Middle English complicacioun, borrowed from Late Latin complicātiōn-, complicātiō "folding together, conglomeration," from Latin complicāre "to fold together, fold up" + -tiōn-, -tiō, suffix of verbal action — more at complicate entry 2

First Known Use

15th century, in the meaning defined at sense 1a

Rhymes for complication

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

complication

noun

com·​pli·​ca·​tion ˌkäm-plə-ˈkā-shən 

1

a

: an act or instance of complicating something

b

: a situation or detail of character that complicates a plot

c

: a complex feature or element

d

: something that makes a situation more complicated or difficult

we were unable to agree when complications arose

2

: a disease or bodily condition existing at the same time as and affecting the course or severity of another disease or condition

Medical Definition

complication

noun

com·​pli·​ca·​tion ˌkäm-plə-ˈkā-shən 

: a secondary disease or condition that develops in the course of a primary disease or condition and arises either as a result of it or from independent causes