From adé ("crown") + ní ("have") + ìkẹ́ ("care, esteem"): "the crown is to be cherished." Linguistically Adéníìkẹ́; contemporary spelling drops one vowel. Shortened to Nike.
Source: Yoruba adé- naming pattern, cross-referenced across yorubaname.com (Adéníkẹ̌, full morpheme breakdown) and Wikipedia (Adenike)