通约

通约	tōng yuē	common measure
通	tōng	to go through / to know well / (suffix) expert / to connect / to communicate / open / to clear / classifier for letters, telegrams, phone calls etc
通	tòng	classifier for an activity, taken in its entirety (tirade of abuse, stint of music playing, bout of drinking etc)
约	yāo	to weigh in a balance or on a scale
约	yuē	to make an appointment / to invite / approximately / pact / treaty / to economize / to restrict / to reduce (a fraction) / concise