THALLIC
Adjective
thallic (comparative more thallic, superlative most thallic)
(inorganic chemistry) Pertaining to or containing the element thallium, especially with valence 3.
(botany) Pertaining to a thallus
Source: Wiktionary
Thal"lic, a. (Chem.)
Definition: Of or pertaining to thallium; derived from, or containing,
thallium; specifically, designating those compounds in which the
element has a higher valence as contrasted with the thallous
compounds; as, thallic oxide.
Source: Webster’s Unabridged Dictionary 1913 Edition