apophasis (n.)

in rhetoric, "a denial of an intention to speak of something which nonetheless is hinted at," 1650s, from Late Latin apophasis, from Greek apophasis "denial, negation," from apophanai "to speak off," from apo "off, away from" (see apo-) + phanai "to speak," related to pheme "voice," from PIE root *bha- (2) "to speak, tell, say."