bub (n.)

• aunt
• auntie
• boy
• brethren
• brother
• buck
• bud
• buddy
• colt
• cousin
• cub
• daughter
• father
• fellow
• fledgling
• grandnephew
• grandniece
• granduncle
• great-aunt
• great-uncle
• hobbledehoy
• lad
• laddie
• master
• mother
• nephew
• niece
• pup
• puppy
• schoolboy
• sis
• sissy
• sister
• son
• sonny
• stepbrother
• stepsister
• unc
• uncle
• whelp
• youth