好高骛远

好高騖遠
hàogāowùyuǎn
  1. to bite off more than one can chew (idiom)
  2. to aim too high

CEDICT

to bite off more than one can chew

Wiktionary

语本《宋史．卷四二七．道学列传一．程颢》：「病学者厌卑近而骛高远，卒无成焉。」形容一味地嚮往高远的目标而不切实际。

重編國語辭典

一味地嚮往高远的目标而不切实际

維基詞典

Entry Composition

1 好 hào to be fond of; to have a tendency to; to be prone to
2 高 gāo
  1. high
  2. tall
  3. above average
  4. loud
  5. your (honorific)
3 骛 wù
  1. (bound form) to rush about
  2. to strive for
4 远 yuǎn
  1. far
  2. distant
  3. remote
  4. (intensifier in a comparison) by far
  5. much (lower etc)

Related entries

贪多嚼不烂 tānduōjiáobùlàn to bite off more than one can chew (idiom)