1 PHRASAL VERB 不懈地致力(于);埋头(于) If you hammer away at a task or activity, you work at it constantly and with great energy. 不懈地致力(于);埋头(于)
2 PHRASAL VERB (尤指因不赞成而)反复谈论(某观点或话题) If you hammer away at an idea or subject, you keep talking about it, especially because you disapprove of it. (尤指因不赞成而)反复谈论(某观点或话题)