This is the 7214th most frequent Dutch word.
beloofden
"Promised" (past tense plural of "beloven").
Here, 'beloofden' signifies a commitment made in the past by the children to perform an action.
De kinderen beloofden om hun kamer schoon te maken.
The children promised to clean their room.
'Beloofden' describes a past action of making a promise involving 'we' as the subject and the intention to provide assistance.
We beloofden hem om te komen helpen.
We promised him to come help.
'Beloofden' is used here in the past tense to indicate a promise made by plural subjects, referring to their intention.