In Lynne Reid Banks's novel The Indian in the Cupboard, Boone is the cowboy who first gets to know Omri in Chapter 9. All we know about Boone so far is that he cries easily and likes to ignore Omri.
Little Bear has been chasing Boone and shooting arrows at him, one of which pins Boone's fine cowboy hat to the baseboard (a piece of wood attached to the wall right down by the floor). This is very upsetting to Boone.
When Omri intercedes between Little Bear and Boone to stop the violence, here's what we learn about Boone:
"The cowboy seemed embarrassed and hung his head. 'M'name's Boone. But the fellas all call me Boohoo. That's on account of Ah cry so easy. It's m'soft heart. Show me some 'n sad, or scare me just a little, and the tears jest come to mah eyes. Ah cain't help it.'"
What Boone means is that his nickname is "Boohoo" because he cries very often. ("Boohoo" sounds a little like "Boone" and is another way of saying "wah, wah, wah," or imitating the sound of someone crying big, babyish tears.) Of course, it's not a very nice nickname!
And because we learn what Boone's nickname is right as we're meeting the character and getting to know him, his nickname could be a hint about what he needs to work on before the end of the story. Will his experiences help him become tougher, less likely to cry? It gives us something to think about as we keep reading.