1 general:: Show pride and self-confidence, as in The most important thing she taught us was to walk tall. [Colloquial; mid-1900s]
American Heritage Idioms
2 general:: Phrase(s): walk tall Fig. to be brave and self-assured. • I know I can walk tall because I’m innocent. • You go out on that stage and walk tall. There is no reason to be afraid.
McGrawhill's American Idioms And Phrasal Verbs