‖a. [ NL., fr. Gr. qy`mos. ] (Anat.) Of, pertaining to, or designating, the thymus gland. -- n. The thymus gland. [ 1913 Webster ]

Thymus gland, or
Thymus body, a ductless gland in the throat, or in the neighboring region, of nearly all vertebrates. In man and other mammals it is the throat, or neck, sweetbread, which lies in the upper part of the thorax and lower part of the throat. It is largest in fetal and early life, and disappears or becomes rudimentary in the adult. The thymus gland functions as the site of maturation of T-lymphocytes (T-cells), which confer cell-mediated immunity on the host organism; thus, removal or malfunciton of the thymus can lead to absence of cell-mediated immunity, and a consequent loss of resistance to infection. [ 1913 Webster +PJC ]