keep one's pecker up

From pecker, meaning "nose", by analogy with beak.

• "“Of course you will,” said Wraysford, cheerily; “it’s hard lines at first. Keep your pecker up, young ’un.” The young ’un, despite this friendly advice, felt very far from keeping up his pecker. But he did his best, and worked his face into a melancholy sort of a smile."
• ", Episode 12, The Cyclops --Keep your pecker up, says Joe. She'd have won the money only for the other dog."
• ""Nerves a bit dicky, eh? Playing a tune to keep your pecker up?""
• "All you need is a box of goodies to keep your pecker up, ..."

• keep one's chin up