From Longman Dictionary of Contemporary Englishhang back phrasal verb1 to stay a short distance away from someone or something, and not go too near them Instinctively he hung back in the shelter of a rock.2 WILLINGto not say or do something because you are shy or afraid → hang→ See Verb table
Examples from the Corpus
hang back• Ambitious men will not wait and unscrupulous men will not hang back.• Faith steps forward; doubt hangs back.• We must all join in this - there is no room for anyone to hang back.• Anna was hanging back and trying to open her mouth.• I propel Rainbow towards her, but hang back myself, struggling to remember the proper formula for deflecting these desperate wanderers.• He came reluctantly, hanging back when I took his hand.• She was hanging back with him, pretending to be interested in some insect on a berry plant.• After that, I stuck to business, trying to hang back within myself. 