Ornate, rococo, baroque, flamboyant, florid can all mean elaborately and often pretentiously decorated or designed.
Ornate is applicable to anything heavily adorned or ornamented or conspicuously embellished.
Rococo basically applies to a French architectural style originating in the eighteenth century and characterized chiefly by the extravagant and often fantastic use of curves, shellwork, and fanciful excrescence. The term therefore implies the ornateness of design characteristic of this decorative style especially as evident in architectural details, in furniture, and in mirror and picture frames. It is often extended to describe a style (as in painting or writing) that seems tastelessly or meaninglessly ornate or overadorned.
Baroque, which is sometimes interchanged with rococo, basically applies to a style of art and architecture which prevailed from the latter part of the sixteenth century to nearly the end of the eighteenth century and which emphasized energy in conception, amplitude in design, the use of dynamic contrasts, extremely high relief, and the employment of curved and often contorted forms.
In its extended sense baroque may suggest more grotesqueness and extravagance and less fancifulness than rococo, although it too may imply tasteless ornamentation.
Flamboyant basically applies to a late French Gothic architectural style characterized by curves that suggest ascending flames (as in the tracery of windows). In its more general application flamboyant can suggest ornateness but more often stresses such elements as excess of color, conspicuous vigor and dash, or bold and daring display that suggest the freedom and brilliancy of flames.
Florid implies richness, usually overrichness, in details, shown particularly in the use of color, figures of speech, or flourishes, for their own sake; it implies, therefore, showy and ostentatious embellishment.