oyster shell lime
Lime made by burning oyster shells; used historically in plaster, mortar, and as a whitewash.
In old Japanese architecture, oyster shell lime was used for walls.
Standard kanji spelling for oyster shell lime.
Mixed kanji-katakana spelling; カキ is a common katakana rendering for 'oyster'.
Compound of 牡蠣 (かき, 'oyster') and 灰 (ばい, 'ash, lime'). The reading ばい for 灰 is a specialized term for lime or ash used in construction.