From Longman Dictionary of Contemporary Englishworry at something phrasal verb1 HBABITEif an animal worries at a bone or piece of meat, it bites and shakes it2 THINK ABOUTif you worry at a problem, you think about it a lot in order to find a solution → worry→ See Verb table
Examples from the Corpus
worry at • Concentrating on Emma would help to keep her worries at bay for a little while.• He found the bank's routine congenial, keeping greater worries at bay.• So that makes me worry at night, for example, and lack of sleep adds to my appearance of tension.• On board the very thought of Keoni was enough to have me lying awake worrying at night.• Party leaders are clearly worried at such a prospect.• We were trying to find out where his particular niches lay and the constant worry at that time was lack of money.• Why, even the Chancellor of the Exchequer is said to be worried at that.• Nancy began to worry at the problem all over again. 