と相まって【とあいまって】

と相まって is a formal expression meaning "combined with," "together with," or "coupled with." It describes a situation where two or more factors come together to produce a combined effect – often one that is greater or more notable than either factor alone. The expression comes from the verb あいまつ相まつ (to combine/to work together), and it is primarily used in written language, news articles, formal speeches, and literary contexts.

The pattern typically highlights how one factor, when combined with another, leads to a particular outcome or intensified result.

Usage notes

• The noun before と represents one contributing factor, and the main clause typically describes the other factor or the resulting outcome.
• Both factors are usually presented as positive or neutral contributors to the result, though the result itself can be either positive or negative.
• This expression is quite formal and is rarely used in casual conversation. In everyday speech, one might use 〜～もくわわって加わって or simply 〜～と〜～で to express a similar idea.
• A related form is とも相まって, which is the same meaning with も added for emphasis.