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Jyutping m4 ding2
Pinyin wú dìng

Definitions (粵典–words.hk)
  1. 形容詞
    講唔​埋​;​表示​有​可能​;​一般​用​於​謂語​之​後​,​通常​同​「​都​」​一齊用
    can't say for sure; usually used to highlight some possibility
    • 可能佢有咗都唔定。
      可能佢有咗都唔定。
      ho2 nang4 keoi5 jau5 zo2 dou1 m4 ding2.
      She could be pregnant, maybe.
  2. 近義詞
    未定
Definitions (Kaifangcidian)
  1. 說不定 – 说不定
  2. 沒準兒 – 没准儿
  3. 說不準 – 说不准
  4. 不一定

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Jyutping m4 ding6
Pinyin wú dìng

Definitions (粵典–words.hk)
  1. 形容詞
    講唔​埋​;​表示​有​可能​;​一般​用​於​謂語​之​後​,​通常​同​「​都​」​一齊用
    can't say for sure; usually used to highlight some possibility
    • 可能佢有咗都唔定。
      可能佢有咗都唔定。
      ho2 nang4 keoi5 jau5 zo2 dou1 m4 ding2.
      She could be pregnant, maybe.
  2. 近義詞
    未定

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Jyutping m4 ding6
Pinyin n2 dìng

Definitions (CC-CANTO)
  1. literal meaning/translation: unsure / unstable; this term is seldom used alone, it is always used with another adjective to form a proper term, to loosely imply something that is 'not set' or 'not fixed' in any particular way
Examples (Tatoeba—Cantonese-English)
  1. Cantonese
    话唔定你啱嘅。
    話唔定你啱嘅。
    waa2 m4 ding6 nei5 ngaam1 ge3 。
    • You may be right about that.
  2. Cantonese
    我话唔定做一阵就会放弃,走去瞓晏觉算。
    我話唔定做一陣就會放棄,走去瞓晏覺算。
    ngo5 waa6 m4 ding6 zou6 jat1 zan6 zau6 wui2 fong3 hei3 , zau2 heoi3 fan3 ngaan3 gaau3 syun3 。
    • I may give up soon and just nap instead.
  3. Cantonese
    我坐唔定。
    我坐唔定。
    ngo5 zo6 m4 ding6 。
    • I can't sit still.
Examples (粵典–words.hk)
  1. Cantonese
    话唔定佢都钟意你呢。
    話唔定佢都鍾意你呢。
    waa6 m4 ding6 keoi5 dou1 zung1 ji3 nei5 ne1.
    • 説不定他也喜歡你呢。
    • Perhaps he likes you too.
  2. Cantonese
    世上有好多嘢都话唔定。
    世上有好多嘢都話唔定。
    sai3 soeng6 jau5 hou2 do1 je5 dou1 waa6 m4 ding6.
    • 世上有很多事都説不定。
    • Nothing is impossible in the world.
  3. Cantonese
    𠮶几只马骝真系坐唔定。
    嗰幾隻馬騮真係坐唔定。
    go2 gei2 zek3 maa5 lau1 zan1 hai6 co5 m4 ding6.
    • The children are too active to sit quietly.
  4. Cantonese
    你唔好谂埋一面啦,话唔定会有意外惊喜呢?
    你唔好諗埋一面啦,話唔定會有意外驚喜呢?
    nei5 m4 hou2 nam2 maai4 jat1 min6 laa1, waa6 m4 ding6 wui2 jau5 ji3 ngoi6 ging1 hei2 ne1?
    • Do not dwell solely on the bad, we may very well be surprised!
  5. Cantonese
    唔好成日睇死啲新同事,玩下手佢升职快过你都唔定。
    唔好成日睇死啲新同事,玩下手佢升職快過你都唔定。
    m4 hou2 seng4 jat6 tai2 sei2 di1 san1 tung4 si6, waan2 haa5 sau5 keoi5 sing1 zik1 faai3 gwo3 nei5 dou1 m4 ding6.
    • Don't be so judgmental to your new colleagues. Who says they won't rise up the ranks faster than you?