insisting — to be emphatic, firm, or resolute on some matter of desire, demand, intention, etc.: He insists on checking every shipment.
persisting — to continue steadfastly or firmly in some state, purpose, course of action, or the like, especially in spite of opposition, remonstrance, etc.: to persist in working for world peace; to persist in unpopular political activities.
resisting — to withstand, strive against, or oppose: to resist infection; to resist temptation.
Four-or-more syllable rhymes
coexisting — to exist together or at the same time.