Young, downy-bearded, or shield-bearer
Jiles is a variant of Giles, which has two primary etymological paths. It likely derives from the Greek 'aigidion' meaning 'young goat' or 'shield of goat skin' (the Aegis), or it may be a medieval English form of Julius, meaning 'youthful'.
Less common today
Jiles isn't in the latest US Top 1000. It last peaked at #6,466 in 1990.
American rock and roll pioneer known as The Big Bopper
US births per 5-year period, 1990βpresent (SSA data).