Accismus is a feigned refusal of something earnestly desired.
The 1823 Encyclopædia Britannica writes that accismus may sometimes be considered a virtue, sometimes a vice.
The Latin term comes from the Greek word is "ἀκκισμός", which, according to Britannica, was "supposed to be formed from Acco (Greek: Akko), the name of a foolish old woman, famous in antiquity for an affectation of this kind." (An 1806 Lexicon manuale Graeco-Latinum et Latino-Graecum agrees with this derivation. However an 1820 Lexicon Graeco-Latinum associates Acco with idle occupation, e.g., chatting with other women or looking into a mirror, hence the Greek coinages Ακκιζειν / Ακκους).
More particularly, in rhetorics, accismus is a figure of speech, a figure of refutation, is a type of irony.