业余

in one's spare time / outside working hours / amateur (historian etc)

surname Ye

line of business / industry / occupation / job / employment / school studies / enterprise / property / (Buddhism) karma / deed / to engage in / already

surname Yu

(archaic) I / me / variant of 餘|余[yu2], surplus

extra / surplus / remaining / remainder after division / (following numerical value) or more / in excess of (some number) / residue (math.) / after / I / me

college for people who attend after work

spare-time education / evening classes

amateur

hobbyist / amateur