Lightly armoured and Steel-plated

Lightly armoured adjective - Equipped with armor heavy enough to provide protection against fire from light arms.

Steel-plated and lightly armoured are semantically related. In some cases you can use "Steel-plated" instead an adjective phrase "Lightly armoured".

Steel-plated adjective - Covered with heavy steel.

Lightly armoured and steel-plated are semantically related. You can use "Lightly armoured" instead an adjective phrase "Steel-plated".