of or containing thallium, esp in the monovalent state
thallous in American English
(ˈθæləs)
adjective
designating or of a chemical compound containing monovalent thallium
thallous in American English
(ˈθæləs)
adjective
Chemistry
containing univalent thallium
Also: thallious (ˈθæliəs)
Word origin
[1885–90; thall(ium) + -ous]This word is first recorded in the period 1885–90. Other words that entered Englishat around the same time include: booster, lineup, reactor, roller coaster, zoom-ous is a suffix forming adjectives that have the general sense “possessing, full of”a given quality (covetous; glorious; nervous; wondrous); -ous and its variant -ious have often been used to Anglicize Latin adjectives with terminations that cannotbe directly adapted into English (atrocious; contiguous; garrulous; obvious; stupendous). As an adjective-forming suffix of neutral value, it regularly Anglicizes Greekand Latin adjectives derived without suffix from nouns and verbs; many such formationsare productive combining forms in English, sometimes with a corresponding nominalcombining form that has no suffix (as -fer and -ferous; -phore and -phorous; -pter and -pterous; -vore and -vorous)