Wiktionary
interj. (context idiomatic English) be happy; cheer up.
WordNet
v. in gymnastics: raise oneself while hanging from one's hands until one's chin is level with the support bar [syn: chin]
Usage examples of "chin up".
Antonietta felt the twist of pain in the region of her heart, but she kept her chin up.
She snapped her chin up and large tears skittered down her drawn cheeks.
Instead, she planted her feet, arched her chin up, and matched him stare for stare.
He slid a knuckle under her jaw and urged her chin up until she had to look at him.
She turned toward him with fire sparking in her eyes, her chin up.
He tilted her chin up so she must look at him, and wiped the tears from her cheeks with the back of one scarred hand.
Lady Anne's face flushed, but she held her chin up, proud daughter of an earl that she was.
He was extremely tall for a Cairhienin, no more than half a head shorter than Rand, and he had a way of standing that made him seem even taller, with his chin up so he seemed to be looking down at everyone else.