adverb taking the 'to' particle, adverb
weep quietly; cry bitterly
Describes crying in a subdued, heartbroken way, often with tears streaming down. Used with verbs like 泣く. The 'bitterly' nuance comes from the depth of sorrow, not loud sobbing.
彼女はさめざめと泣いた。
She wept quietly, tears streaming down her face.