mundane
Meaning: concerned with the world rather than with heaven, commonplace
Usage: He is more concerned with the mundane issues of day-to-day life than with spiritual topics.
prosaic
Meaning: plain, lacking liveliness
Usage: Heather’s prosaic recital of the poem bored the audience.
insipid
Meaning: dull, boring
Usage: The play was so insipid, I fell asleep halfway through.
tedious
Meaning: dull, boring
Usage: As time passed and the history professor continued to drone on and on, the lecture became increasingly tedious.
banal
Meaning: dull, commonplace
Usage: The client rejected our proposal because they found our presentation banal and unimpressive.
vapid
Meaning: lacking liveliness, dull
Usage: The professor’s comments about the poem were surprisingly vapid and dull.