The compound adjective 'warm-hearted' is a relatively modern English formation, built from native Germanic elements. The first element, 'warm', extends its physical meaning of moderate heat into the emotional realm, suggesting kindness and affection. The second element, 'heart', has been a metaphor for the center of feeling and courage since Old English. The suffix '-ed' attaches to the noun compound 'warm heart', transforming it into an adjective meaning 'possessing a warm heart'. This logical construction vividly equates emotional generosity with physical warmth, creating an intuitive and enduring descriptor for a kindly disposition.

Structure: warm (having moderate heat) + heart (center of emotion) + ed (having the quality of) - warm: From Old English 'wearm' (warm), of Germanic origin; related to Dutch 'warm' and German 'warm'. Functions as an adjective describing a literal or figurative quality. - heart: From Old English 'heorte', of Germanic origin; related to Dutch 'hart' and German 'Herz'. Functions as a noun, here used in a compound to represent the seat of emotion. - ed: A suffix forming adjectives from nouns or other adjectives, from Old English '-ede', '-ode', '-ad'. Functions as an adjectival suffix meaning 'having' or 'characterized by'.