(of a young person's behavior or attributes) beyond one's years; adultlike
Definitions (粵典–words.hk)
形容詞
超過年齡上限;年紀太大 over-age
超齡學童
超龄学童
ciu1 ling4 hok6 tung4 over-age pupil
呢個活動係俾五歲以下嘅小朋友㗎,你嘅小朋友似乎超齡喎。
呢个活动系俾五岁以下嘅小朋友㗎,你嘅小朋友似乎超龄㖞。
ni1 go3 wut6 dung6 hai6 bei2 ng5 seoi3 ji5 haa6 ge3 siu2 pang4 jau5 gaa3, nei5 ge3 siu2 pang4 jau5 ci5 fu4 ciu1 ling4 wo3. The activity is for children aged under 5. It seems that your child is over-age.
Definitions (Wiktionary)
verb
to be overage (syn.) 出岁, 過歲, 出歲, 出頭歲, 出头岁, 过岁