[--]

Jyutping bun3 baak3
Pinyin bàn bǎi

Definitions (Wiktionary)
  1. num
    fifty; 50 (chiefly years of age)
    (syn.) 五十
Definitions (Kaifangcidian)
  1. (沒有對應漢語詞彙)

半百 [--]

Jyutping
Pinyin bàn bǎi

Definitions (CC-CEDICT)
  1. fifty (usually referring to sb's age)