(こう)

こう
prefix
high; high-level; advanced
transportation
1. high; elevated
Prefix indicating high level, degree, or quality.
Please be careful of high temperatures.
(こう) + (おん) = high temperature
I want a high-performance computer.
(こう) + 性能(せいのう) = high performance
2. advanced; senior
Prefix indicating advanced level or senior status.
The elderly population is increasing.
(こう) + (れい) = advanced age
Studies get harder in the upper grades.
I want to live energetically even in old age.

(こう)〜 is a common prefix indicating 'high' or 'advanced.'

Compounds

Antonym prefix

(てい)〜 (low)

Usage

(たか) is the standalone i-adjective meaning 'high' or 'expensive.'