There are a lot of synonyms for the phrase "bejewelled head-dress" that one can use in different contexts or scenarios. Some of the possible alternatives include embellished headpiece, bedazzled headdress, ornate tiara, sparkling crown, jeweled hair accessory, decorated headgear, radiant diadem, flashy headband, luxuriant head covering, and glistening ceremonial hat, among others. These terms are just a few examples of the many ways in which one can describe a headpiece adorned with precious stones or gems. Choosing the right synonym depends on the specific context and tone of the piece of writing or the conversation.