Step 1: Read the clue in the definition.
The curve is made of two arcs that bend in opposite directions, joined by a common tangent, with their centres on opposite sides.
Step 2: Check a compound curve.
In a compound curve the arcs bend the same way and their centres lie on the same side, so this does not match.
Step 3: Check a transition curve.
A transition curve has a radius that keeps changing along its length, which is different from two fixed arcs, so this is not it.
Step 4: Check a combined curve.
A combined curve is just a mix of circular and transition curves, again not what the definition says.
Step 5: Match the reverse curve.
Two arcs bending in opposite directions with centres on opposite sides is exactly the description of a reverse curve.
Step 6: State the answer.
The curve described is a reverse curve.
\[ \boxed{\text{Reverse curve}} \]