(rare) one who never laughs (especially at jokes); a mirthless person

Not jovial; never laughing.

plural of agelast

(organic chemistry) Any of various adenine-related bicyclic diterpenoids isolated from the orange sponge Agelas mauritania, structurally related to the agelasines.

plural of agelasimine

(organic chemistry, medicine) Any of a family of naturally-occurring oroidin alkaloids having antitumor properties

plural of agelastatin