Possible Clues:

• Gave the go-ahead to
• Authorised including Arthurian knight in dictionary
• Approved fabulous knight for inclusion in reference work
• Accepted order for cocktail primarily with ale that changed colour with no head
• Greenlit
• Approved sort of ox put back in old herd every now and then
• Little Katharine found in dictionary that's approved
• Approved of order for cocktail primarily with ale that changed colour with no head
• Gave the nod
• Gave informal approval