白食 (baak6 sik6)：Eating, but no need to pay – use in negative way
白撞 (baak3 zong6)：Pretending to be familiar with someone, and mingling into his place to cheat – use in negative way. It can describe both the action and the person who does the action.
例子：The news comes from the following link. https://hk.news.appledaily.com/…/…/article/20171122/57491703
台灣桃園一名婦人「白撞」入新人婚禮白吃白喝，甚至拿走喜餅。
toi4 waan1 tou4 jyun4 jat1 ming4 fu5 jan4 「 baak6 zong6 」 jap6 san1 jan4 fan1 lai5 baak6 hek3 baak6 hot3 ，sam6 zi3 naa4 zau2 hei2 beng2 。
Change it into spoken Cantonese,
台灣桃園嘅一個女人「白撞」去咗一對新人嘅婚禮入面白飲白食，甚至連禮餅都攞走埋。
toi4 waan1 tou4 jyun4 ge3 jat1 go3 neoi5 jan2 「 baak6 zong6 」 heoi3 zo2 jat1 deoi3 san1 jan4 ge3 fan1 lai5 jap6 min6 baak6 jam2 baak6 sik6 ，sam6 zi3 lin4 lai5 beng2 dou1 lo2 zau2 maai4 。
A woman in Taiwan, Taoyuan joined in a wedding banquet of a couple, eating and drinking without pay anything, she even took away the wedding cake.
