lugna sig bedeutet auf Englisch

calm [calmed, calming, calms]▼(to become calm)
verb
[UK: kɑːm] [US: ˈkɑːm]

subside [subsided, subsiding, subsides]▼(to fall into a state of calm; to settle down; to become tranquil; to abate)
verb
[UK: səb.ˈsaɪd] [US: səb.ˈsaɪd]