interest-only

The compound "interest-only" is a modern financial term built from two distinct English words. "Interest" originates from the Latin verb interesse, literally meaning "to be between," which evolved to signify "to concern" or "to make a difference." In legal and financial Medieval Latin, the phrase id quod interest ("that which is the difference") came to denote compensation, eventually crystallizing into the modern monetary charge for borrowed capital. "Only" derives from Old English ānlīċ ("one-like"), emphasizing singularity and exclusivity. Combined, the term's logic is transparent: it describes a financial arrangement where the payment is solely and exclusively the charge for the use of money, with no contribution toward the principal loan amount.

Structure: interest (concern, financial charge) + only (solely) - interest: From Middle English, from Anglo-Norman interest, from Latin interest ("it concerns, it makes a difference"), the third person singular present of interesse ("to be between, to make a difference"). In the financial sense, it evolved from the medieval Latin phrase id quod interest ("the compensation for loss"). - only: From Middle English oonly, onlich, from Old English ānlīċ ("like, similar; solitary"), from ān ("one") + -līċ ("-ly, -like"). The sense of "solely, exclusively" developed from the idea of being "one and no more."