Correct spelling, explanation: the word conclusion is a noun that originates from the Old French conclusion conclusion, result, outcome, from the Latin conclusionem (nominative conclusio). It is worth noticing that when it comes to spelling, the word conclusion doesn’t feature two -s letters next to each other. Conclussion is just a mistake.

Definition of conclusion:
noun, a judgement or decision reached by reasoning
After carefully analyzing the data, we reached the conclusion that the new marketing strategy significantly boosted sales.
In conclusion, the research findings demonstrate a clear correlation between exercise and improved cognitive function.

Collocations with conclusion:
Some most commonly used collocations include:
1. In conclusion – used to summarize or sum up the main points or arguments made in a discussion or presentation.
In conclusion, it is evident that climate change poses a significant threat to our planet.
2. Final conclusion – the ultimate or definitive decision or judgment reached after careful consideration.
The jury deliberated for hours before reaching their final conclusion on the case.
3. Logical conclusion – a result or inference that can be logically derived from a given set of facts or premises.
Based on the evidence presented, it is a logical conclusion that the suspect was at the scene of the crime.
4. False conclusion – a decision, judgment, or belief that is incorrect or inaccurate based on the available evidence or reasoning.
Despite the lack of empirical evidence, he hastily jumped to a false conclusion, assuming that all cats are allergic to water.

Incorrect spelling, explanation: it is quite easy to spell the word conclusion: it doesn’t contain any double vowels or double consonants. Some people, however, make the mistake of writing it with the double -s, but this has no etymological explanation. Remember that the only correct form is conclusion, not conclussion.

Incorrect spelling