tranquillizzare significa in inglese

calm down▼(To cause to become less excited)
verb
[UK: kɑːm daʊn] [US: ˈkɑːm ˈdaʊn]

reassure [reassured, reassuring, reassures]▼(to assure anew; to restore confidence to; to free from fear or self-doubt)
verb
[UK: ˌriːə.ˈʃʊə(r)] [US: ˌriə.ˈʃʊr]