This is the 847th most frequent Icelandic word.
opnuð
"Opnuð" means "opened" in English.
Here, 'opnuð' is used as a verb in the past participle form, agreeing with the feminine singular noun 'dyrið' (door).
Dyrið var opnuð þegar við komum.
The door was opened when we arrived.
'Opnuð' functions here as the action performed by the subject 'konan' (the woman), showing direct action.
Konan opnuð gluggann til að inn kom ferskt loft.
The woman opened the window to let in fresh air.
In this example, 'opnuð' is part of a passive voice structure, indicating the state of the object 'sögubókin' (storybook).