Don means put on. Donned would be the past tense of that.
Jimmy donned his cap and walked to the market.
She donned her hat and gloves, ready to go out in the wind.
Ralph donned his cap and cape and went to feed the horses.
Spirits were high as we all donned our pink t-shirts and decorated the bus with banners and ballons.
She donned a gown of flowing silk.
Donned means put on, as in "She donned her cap," which means she put on her cap.
The synonym for donned is to put on.
To 'don' is to put on, so 'donned' is the past tense form of the verb 'don' "I donned my warm coat when I saw the wind was blowing outside" Donned is a past tense verb.
Drop to the ground, don protective mask (if not donned already)
trousers
Put on, as clothing.
John Casey