Inseparable means impossible to part from one another. Inseparable friends, the two are inseparable, inseparable from the question.
Of people it is affectionate and slightly exaggerated. Of ideas it is an argument: saying two things are inseparable claims you cannot discuss one without the other, which is a strong move and usually the point being made.
1adjectiveinseparableImpossible to part from one another.
“The two girls met on the first day of school and have been inseparable ever since.”
inseparable is a quality.
Latin inseparabilis, in-, not, plus separare, to separate — se, apart, plus parare, to prepare.
Latin
īnsēparābilis
Middle French
inséparable
English, today
inseparable
From Middle English -, from Middle French inséparable, from Latin īnsēparābilis. Constructed as in + separable.
Etymology from Wiktionary, CC BY-SA