主次

the important and the less important / primary and secondary

owner / master / host / individual or party concerned / God / Lord / main / to indicate or signify / trump card (in card games)

next in sequence / second / the second (day, time etc) / secondary / vice- / sub- / infra- / inferior quality / substandard / order / sequence / hypo- (chemistry) / classifier for enumerated events: time

to invert the importance of things (i.e. stress the incidental and neglect the main point) / lacking a sense of perspective / to put the cart before the horse