"Vapid expressions" refers to an uninteresting, trite or shallow language that brings no intellectual stimulation or novelty. Although there are many words that can be used as synonyms, some examples include banal, insipid, tedious, mundane, bland, commonplace, unimaginative, and unoriginal. All these words describe language that lacks excitement, creativity and energy. Other words that can be used include colorless, uninspiring, flat, pale, lifeless, and dull. People often use vapid expressions when they run out of ideas, lack imagination, or attempt to sound smart without actually saying anything of value. To avoid sounding bland or boring, try using more vibrant words or phrases that communicate your message with clarity and precision.