Often written in old manuscripts or transcriptions of them, denoting a capital F.

plural of jewel-neck

(organic chemistry) Either of the two isomeric carboxylic acids, normal butyric acid and isobutyric acid, with the chemical formula C₃H₇COOH, occurring in animal milk fat.

Any of the genus Thelazia of nematode worms that parasitize the eyes of their hosts.