Yearnful comes from yearn + -ful, from Old English ġiernan ('to desire, strive'), from Proto-Germanic *gernijaną, from Proto-Indo-European *ǵʰer- ('to like, want'). In current use it is an adjective meaning "full of yearning; longing or wistful". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The suffix -ful marks possession or fullness of the quality named by the base. The surface form is compositional: its joined elements remain visible in the modern word. The historical chain includes Old English ġiernan and Proto-Indo-European *ǵʰer-. Related English forms include yearn and yearning. The word's history is thus visible in its construction: the components remain interpretable even after the whole expression has settled into a conventional English meaning.