小哥哥

1. • little boy who is older than another young child (e.g. his playmate)
2. • (slang) amiable form of address for a young man of about one's own age or a little older

     neologism c. 2017

Character by character

• 小(xiǎo)small
• 哥(gē)elder brother
• 哥(ge)elder brother