Alkener

Alkener is a term that has appeared in various contexts but is not an established scientific term in modern chemistry. In contemporary chemistry the term used for hydrocarbons with at least one carbon–carbon double bond is alkene; 'alkener' is not recognized by IUPAC as a separate class.

Etymology and history: The form 'alkener' is occasionally found as a misspelling, a historical variant, or a dialectal/translation artifact of 'alkene.' It appears sporadically in older texts or non-English sources, but such usage has largely fallen out of favor.

Other uses: Beyond chemistry, alkener may occur as a surname, a fictional character name, or a brand/product label. In these contexts it does not have a universal technical meaning.

In summary, alkener is not a standard chemical term; for discussions of unsaturated hydrocarbons, 'alkene' is the correct term.