noun, noun or participle which takes 'suru'
drying and hardening
Describes the process by which something loses moisture and becomes solid, often used for materials like clay, paint, or glue.
接着剤が乾固するまで、そのまま押さえてください。
Hold it in place until the adhesive dries and hardens.
乾燥 means simply 'drying' or 'dehydration', without the hardening aspect. 乾固 emphasizes the resulting solidification.
Compound of 乾 (dry) and 固 (harden). The reading かんこ follows the on'yomi of both characters.