gamma; Γ, γ +

(Greek: Γ, γ; the third letter of the Greek alphabet; corresponding to g, as in go and as a numeral, it indicates 3)

gamma-ray well logging
Measurement of gamma-ray intensity versus depth down a well bore.

Used to identify rock strata, their positions, and their thicknesses.

Imaging by means of gamma radiation; scintigraphy (a diagnostic test in which a two-dimensional picture of a body radiation source is obtained through the use of radioisotopes).
1. An immunodeficiency condition arising from a deficiency of gamma globulin in the blood, either present from birth or acquired later during life.
2. Abnormally low levels of all classes of immunoglobulins in the blood.

You can see all of the letters of the Greek Alphabet on this page.