1.Definition: completely ordinary and unremarkable

"Air travel has now become commonplace", "Commonplace everyday activities"

2.Definition: not challenging; dull and lacking excitement

Related Adjective(s):humdrum, prosaic, unglamorous, unglamourous

3.Definition: repeated too often; overfamiliar through overuse

"His remarks were trite and commonplace"

Related Adjective(s):banal, hackneyed, shopworn, stock, threadbare, timeworn, tired, trite