A "courageous pledge" can be replaced with a variety of synonyms that convey similar sentiments. One such synonym is "fearless vow," which highlights the fearlessness and boldness required to make the pledge. Another synonym is "brave promise," emphasizing the bravery and determination needed to keep the pledge through difficult situations. "Valiant commitment" is also a fitting synonym, as it signifies the noble and heroic nature of the pledge. A "bold declaration" is another alternative, emphasizing the confidence and conviction behind the statement. Overall, any of these synonyms capture the essence of a "courageous pledge" and convey the same level of commitment and determination required to make such a promise.