What part of speech is “walked”

'walked' is past for of the verb 'walk' that is used to express past tense. It is the past tense of 'walk,' meaning 'to change location by using one's feet to move along, usually in a steady manner and for a certain distance.'

1. Last night, I walked around the block.

2. He walked confidently into the room.

3. We walked together in silence for a few minutes.