Listen Up!' is an expression used to get someone's ATTENTION and can be used in a variety of contexts. The crossword solutions for this term include ATTENTION (9 letters), HARK (4 letters), HEY (3 letters), HEED (4 letters), HEARKEN (7 letters), NOWHIS (7 letters), SEEHERE (7 letters), SILENCE (7 letters), LOOKHERE (8 letters), TAKEHEED (8 letters), NOWHEARTHIS (11 letters), PAYATTENTION (12 letters), and ATTENTIONPLEASE (15 letters). All of these words are synonyms for the phrase 'Listen Up!' and can be used to get someone's ATTENTION.