n.
Variant: or thy · rox · in
Pronunciation: th ī - ' räk- ˌ s ē n, -s ə n
Function: noun
Etymology: thyr- + ox y + in dol e
Date: 1918
: an iodine-containing hormone C 15 H 11 I 4 NO 4 that is an amino acid produced by the thyroid gland as a product of the cleavage of thyroglobulin, increases metabolic rate, and is used to treat thyroid disorders