Synonyms for Humanitarian (same or very similar meaning)
WordNet sense 1 (someone devoted to the promotion of human welfare and to social reforms):
do-gooder, improver
WordNet sense 2 (marked by humanistic values and devotion to human welfare):
humanist, humanistic, human-centered, human-centred
WordNet sense 3 (marked or motivated by concern with the alleviation of suffering):
humane
From the ODE community, based on WordNet
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