LacrimationShedding of tears, especially an excessive and/or involuntary flow.RelatedSynonyms:tearingRelated Articles:Cluster HeadacheEFNS Guidelines on the Treatment of Cluster Headache and Other Trigeminal Autonomic CephalalgiasTrigeminal Autonomic Cephalgias Due to Structural LesionsHigh-Flow Oxygen for Treatment of Cluster Headache A Randomised TrialCluster headache in women: Clinical characteristics and comparison with cluster headache in men