Sunshiny comes from sunshine (a compound of Old English sunne 'sun' and scīn 'shining') plus the adjectival suffix -y, an English formation. The historical chain includes Old English sunne and Old English scīn. The quoted older senses, "sun" and "shining", supply the semantic anchors for sunshiny. The formation is best read as suffixal, compound, and borrowed: the word sunshiny carries its older form-history into a compact English lexical shape. In present English it is used as a adj, "bright with sunshine; cheerful". Related English forms include sun and sunshine. The result is a adj whose etymology preserves both the older form and the later English specialization.