(medicine, underwater diving) A mixture of helium and oxygen used as a breathing gas.

(botany) That thrives in sunny, dry conditions

(organic chemistry) Any of a group of benzofurans (especially 10-(1,3-benzodioxol-5-yl)-9H-[2]benzofuro[6,5-g][1,3]benzodioxol-7-one) that suppress gene expression of human hepatitis B virus