WordNet sense 1 (an early bicycle with a very large front wheel and small back wheel):

ordinary bicycle

WordNet sense 2 (being neither good nor bad):

indifferent

WordNet sense 3 (found in the ordinary course of events):

everyday, quotidian, routine

WordNet sense 4 (completely ordinary and unremarkable):

commonplace

WordNet sense 5 (to be expected; standard):

common

WordNet sense 6 (lacking exceptional quality or ability):

average, fair, mediocre, middling