"pertaining to or in the manner of conspiracy," 1843; see conspirator + -ial. Related: Conspiratorially.
Entries linking to conspiratorial
conspirator n.
"one who plots or acts on evil or unlawful designs," c. 1400, conspiratour, from Old French conspirateur, from Latin conspiratorem (nominative conspiratorio), noun of action from past-participle stem of conspirare "to agree, unite, plot," literally "to breathe together" (see conspire).
Conspirer is attested from 1530s, from Anglo-French conspirour. Fem. form conspiratrice is from early 15c.; conspiratress is from 1760. Related: Conspiratory.
-ial
adjectival word-forming element, variant of -al (1) with connective -i-. From Latin -ialis, in which the -i- originally was from the stem of the word being attached but later came to be felt as connective.