The phrase "letted through" implies giving permission to someone or something to pass through a particular area or situation. Some synonyms for "letted through" include granted access, allowed passage, permitted entry, authorized admittance, and sanctioned inclusion. These synonyms indicate a formal and deliberate decision to allow someone or something to proceed to a specific location or situation. Other related phrases that convey a similar meaning include cleared for entry, approved for access, and given the green light. Regardless of the specific wording used, all of these phrases convey the idea of granting permission to proceed through a particular area or situation.