(mathematics) Initialism of highest common factor. / (computing, humorous) Initialism of Halt and Catch Fire (an instruction that locks up a processor).

plural of HCG

(astronomy) Abbreviation of Hickson compact group. / (medicine) Abbreviation of HLA complex group. (human leukocyte antigen complex group) / (medicine) Abbreviation of human chorionic gonadotropin.

Initialism of hexagonal close-packed.

(chemistry) Initialism of hydrogen cyanide. / (numbers) Initialism of highly composite number.

(chemistry) fulminic acid

(organic chemistry) formic acid

plural of HCF

(biochemistry) hemicatenated DNA

plural of HCI