|Origin:||Probably from a Scandinavian language|
1 [intransitive always + adverb/preposition]
to move in an unsteady way, as if you cannot see properly
Someone was blundering about in the kitchen.
blunder into/past/through etc something
Phil came blundering down the stairs.
to make a big mistake, especially because you have been careless or stupid:
They blundered badly when they gave him the job.