It could be:
* A shortened form of "detention": This would be used in casual conversation, but wouldn't be found in formal writing.
* An abbreviation for "detachment": This is less common but possible in specific contexts.
* A misspelling of another word: It's possible you're thinking of a word that sounds similar, but is spelled differently.
Could you please provide more context or the full sentence where you saw this word? This will help me understand what you're looking for.