Alma is a variant of the name Amalia, meaning 'nourishing', 'kind', 'imitating', 'rivaling' (Latin), 'girl', 'secret', 'maiden' (Hebrew), 'soul' (Italian) and 'work' (Gothic).
Latin
From The Name Book: Over 10,000 Names - Their Meaning, Origins, and Spiritual Significance by Dorothy Astoria.