Spicy, a. [Compar. Spicier; superl. Spiciest.]
Etymology: [From Spice.]
1. Flavored with, or containing, spice or spices; fragrant; aromatic; as, spicy breezes. "The spicy nut-brown ale." Milton. Led by new stars, and borne by spicy gales. Pope.
2. Producing, or abounding with, spices. In hot Ceylon spicy forests grew. Dryden.
3. Fig.: Piquant; racy; as, a spicy debate.
Syn. -- Aromatic; fragrant; smart; pungent; pointed; keen. See Racy.
Shades of meaning
Fernald has no entry of its own for spicy; he lists it under racy.
Where he writes about it:
As applied to literary products, racy refers to that which has a striking, vigorous, pleasing originality; spicy to that which is stimulating to the mental taste, as spice is to the physical; piquant and pungent in their figurative use keep very close to their literal sense. — from racy