to make a vow or a pledge casually without really thinking about following through with it
Definitions (粵典–words.hk)
語句
輕易、隨便許下一啲承諾，貪口爽而冇諗住實現 to make easy promises without intention to keep them; literally: to swear an oath as if eating lettuce
你信佢哋？班政棍一向慣咗發誓當食生菜㗎啦！
你信佢哋？班政棍一向惯咗发誓当食生菜㗎啦！
nei5 seon3 keoi5 dei6? baan1 zing3 gwan3 jat1 hoeng3 gwaan3 zo2 faat3 sai6 dong3 sik6 saang1 coi3 gaa3 laa1! You really trust them? Those politicians are used to making easy promises as if eating lettuce!
參看
發誓當食生菜
Definitions (Kaifangcidian)
無信義 – 无信义
隨口發誓 – 随口发誓
隨便起誓 – 随便起誓
全無信義 – 全无信义
說話從不算數 – 说话从不算数
起誓當白饒 – 起誓当白饶
隨便發誓 – 随便发誓
Examples (粵典–words.hk)
Cantonese
誓愿当食生菜
誓願當食生菜
sai3 jyun6 dong3 sik6 saang1 coi3
to make easy promises without intention to keep them; literally: to swear an oath as if eating lettuce