In the line "खूब लड़ी मर्दानी वह तो झाँसी वाली रानी थी", the word "मर्दानी" (Mardani) means:

In the context of this famous historical poem, the word "Mardani" describes a woman who possesses immense valor, bravery, and warrior skills traditionally associated with battlefield heroes, signifying a heroic or courageous woman ($\text{Veerangana}$).