WordNet sense 1 (found in the ordinary course of events):

mundane, quotidian, routine, unremarkable, workaday

WordNet sense 2 (not exceptional in any way especially in quality or ability or size or degree):

ordinary

WordNet sense 3 (suited for everyday use):

casual

WordNet sense 4 (not formal):

informal

WordNet sense 5 (within normal everyday experience; common and ordinary; not strange):

familiar