Which of the following best describes "loan words"?

The term "loan words" refers specifically to words that have been borrowed from one language and incorporated into another. This process often occurs when speakers of one language encounter concepts or items unique to another culture, prompting the adoption of those words into their own lexicon. Loan words retain much of their original pronunciation and meaning, although they may be adapted to fit the phonetic and grammatical rules of the borrowing language.

The other options do not accurately capture the definition of loan words. Words originating from multiple roots pertains more to etymology than to borrowing. Words that have been changed in function refer to instances where the grammatical role of a word shifts, while words that have broad meanings relate to semantic evolution rather than the process of borrowing across languages. Thus, the correct understanding of loan words is reflected in the choice that identifies them as words borrowed from other languages.