HSK10+
chǔ
foundation
Phonosemantic compound. 石 represents the meaning and 楚 represents the sound.
石 Meaning component
shí, dàn
stone
楚 Sound component
clear
Seal script
Regular script
础 (礎)
foundation stone, plinth; foundation; base
基础
base
础
基础课
basic course
Academia Sinica
Make Me a Hanzi
Unicode
Dong Chinese
CC-CEDICT
SUBTLEX-CH
MTSU Chinese text computing
漢語多功能字庫