From Longman Dictionary of Contemporary Englishwalk tallwalk tallCONFIDENTto be proud and confident because you know that you have not done anything wrong → walk
Examples from the Corpus
walk tall• Whether they won or lost, they should walk tall.• She walks tall and straight, a little stiff.• I walked taller and the ground I walked on seemed firmer.• They proceeded slowly back uphill, with Hyacinth walking taller at each step as she appreciated the glamour of her new condition.• Latinos have walked taller ever since.• We walk tall, no longer cowed by writs.• And walking tall: Out of the wheelchair, and into karate.• And walking tall: Why Harry the penguin loves his new mum. 