I have a field in Account : Account Type. For a particular set of users with language en_us this field is translated to : HCP/HCO Type Now, in another related object of Account say Acct_child, Account lookup field Acct__c exists. Now, while selecting a particular account from the lookup dialog, this HCP/HCO Type field appears, inside the lookup dialog search layout. For this particular occasion I need it to be translated to HCP Type, instead of HCP/HCO Type. Is that possible using configuration?
No, this isn't possible using configuration. The label for a field can have translations for different langauges, but it will always be displayed the same across the application, no matter where the user is viewing it.