通同

to collude / to gang up on

like / same / similar / together / alike / with

see 衚衕|胡同[hu2 tong4]

to go through / to know well / (suffix) expert / to connect / to communicate / open / to clear / classifier for letters, telegrams, phone calls etc

classifier for an activity, taken in its entirety (tirade of abuse, stint of music playing, bout of drinking etc)