testa-, test- +

1. A shell, a loose or rigid, secreted or agglutinated, protective shell or shell-like covering or exoskeleton, seen in various invertebrates, including certain protozoa and echinoderms.
2. An envelope or skeleton of certain protozoa in the subphylum Rhizopoda consisting of organic, fibrous, calcareous, silicate, strontium sulfate, or other materials, often in a highly complex form with numerous apertures through which axopodia or filopodia of cytoplasm protrude.

1. Seed coat; outer covering of a seed.
2. A shell; protective outer layer of seeds of flowering plants.
3. Episperm; the skin or coat of a seed; especially, the outer coat.
4. The outer, usually hard, integument, or coat, of a seed.

Covered with a shell; a former order corresponding to the subclass Testacealobosia in the current classification.

A subclass of amebas characterized by the presence of a test (shell) with single or multiple apertures for protrusion of pseudopodia.

The science concerned with testaceans, or shellfish; the description of shellfish.

The science of testaceous (hard shell) mollusks; conchology.

1. Having a shell or test.
2. Having the reddish brown color of bricks or baked clay.

Fretfully; peevishly; with petulance (easily irritated or annoyed).

Fretfulness; peevishness; petulance; feeling easily irritated.

Testiness is a disposition or aptness to be angry.

1. Easily irritated or annoyed.
2. Irritated, impatient, or exasperated; peevish; such as, a testy cab driver; a testy refusal by the clerk to help.
3. Etymology: from Late Latin testa, "skull"; in Latin, "pot, shell".

To see the "head" in testy, it is necessary to look back at the Old French word testu, which is the source of testy. Testu (literally "heady") is derived from the Old French word teste, “head” (Modern French tête).

In English testy developed another sense, “aggressive, contentious”; which passed into the sense now used as, "irritable".