coincidentally

UK: /kəʊˌɪnsɪˈdɛntəli/ | US: /koʊˌɪnsɪˈdɛntəli/

Definition
  1. adv. by chance; happening at the same time without planning

  2. adv. in a way that seems deliberately arranged but is actually accidental

Structure
coincident <happening together>al <adjective suffix>ly <adverb suffix>
Etymology

The word "coincidentally" stems from the Latin coincidere ("to fall upon together"), combining co- (together) + incidere (to fall upon). The root "coincident" entered English via French in the 17th century, originally describing events that aligned in time. The suffix -al (from Latin -alis) forms adjectives, while -ly (Old English -lice) converts them into adverbs. The modern sense of accidental convergence reflects the word’s logical progression from literal simultaneity to perceived serendipity.

Examples
  1. We ran into each other coincidentally at the airport.

  2. Coincidentally, both novels were published on the same day.

  3. Their research topics overlapped coincidentally.

  4. Coincidentally, the power outage occurred during the live broadcast.

  5. She wore the same dress as me, quite coincidentally.