Meanings

complication

writing side by side

classifying together

having both (at the same time)

occurring simultaneously

joint establishment (esp. schools of different levels or different courses of study)

combined use

to use jointly

merger

concurrence

double play

complication (in illness)

to consider together

reading (two or more books, etc.) at the same time

merger (of companies, towns, etc.)

placing side by side

coexistence

merger

concurrent offenses

uniting