to keep feelings or thoughts, especially negative ones, in your mind for a long time
در دل داشتن, در دل نگه داشتن, نگه داشتن در دل
The arsonist may harbour a grudge against the company.
She began to harbour doubts about the decision.
to harbour thoughts of revenge
He still harbours ambitions of playing professional soccer.
He still harboured doubts about her honesty.