コップがこなごなに割れた。

glass (i.e. drinking vessel); tumbler; cop (police officer)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

in very small pieces

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

to break; to be smashed; to split; to crack; to fissure; to be torn; to be divided; to cleave; to come to light; to be identified; to be established; to become clear