Insinuation, innuendo mean covert suggestion or a covert allusion to something.
Insinuation applies chiefly to a remark, comment, or question which conveys or seems to convey a hint or implication, often one that is discreditable to the person at whom it is aimed.
Innuendo more often applies to the method of covert suggestion than does insinuation, and when it applies to a definite instance, it is referable to meaningful smiles, glances, inflections, as well as to remarks; in both cases the term definitely implies a suggestion of something that is injurious to the reputation of the person concerned.