The term 'LACKING ZIP' can be described by four crossword solutions: BLAH (4 letters), VAPID (5 letters), LIFELESS (8 letters), and LANGUID (7 letters). BLAH is an adjective meaning dull or uninteresting. VAPID is an adjective meaning lacking in liveliness, spirit, or zest. LIFELESS is an adjective meaning having no animation or vitality. Lastly, LANGUID is an adjective meaning lacking energy or enthusiasm. All of these words describe the term 'LACKING ZIP', which means to be without energy, enthusiasm, or liveliness.