Question type - List (Radio)/16/en
From LimeSurvey Manual
Label for 'Other:' option (other_replace_text)
Short text string to replace the text "Other" as label for the "other" option.
Note: You can make use of this attribute if you have previously enabled the "other" option located under the general options tab.
Entering a value of "Alternative:" for this attribute would result in the word "Alternative:" being used instead of "Other".
Issue in LimeSurvey 4.X : It is extremely important to note that this question attribute should only be used in single-language surveys. A translation will be attempted but will only be successful if the translation already exists in the alternate language file (i.e.: translation cannot be made on a survey-by-survey basis). Therefore, to translate your other text, you have to add your other_replace_text to the english .mo file (because this is LimeSurveys baselanguage) and translate this String in each of your surveys languages .mo files.