Merriam-Webster Collegiate Dictionary - capsule

 I. noun  Etymology: French, from Latin capsula, diminutive of capsa box — more at case  Date: circa 1693  1.  a. a membrane or sac enclosing a body part (as a knee joint or kidney)  b. either of two layers of white matter in the cerebrum  2. a closed receptacle containing spores or seeds: as  a. a dry dehiscent usually many-seeded fruit composed of two or more carpels  b. the spore case of a moss  3. a shell usually of gelatin for packaging something (as a drug or vitamins); also a usually medicinal or nutritional preparation for oral use consisting of the shell and its contents  4. an often polysaccharide envelope surrounding a microorganism  5. an extremely brief condensation ; outline, survey  6.  a. a compact often sealed and detachable container or compartment  b. a small pressurized compartment or vehicle (as for space flight or emergency escape)  II. transitive verb  (~d; capsuling)  Date: 1859  1. to equip with or enclose in a ~  2. to condense into or devise in a compact form  III. adjective  Date: 1938  1. extremely brief  2. small and very compact