noun

• A severe pang or spasm of pain, especially one experienced when the uterus contracts during childbirth, or when a person is about to die.
  "As if their own indignant earth, / Which gave the sons of England birth, / Had felt their blood upon her brow, / And shuddering with a mother's throe, / Had turned every drop of blood, / By which her face had been bedewed / To an accent unwithstood, / As if her heart had cried aloud: […]"
• (figuratively, usually in the plural) A hard struggle, especially one associated with the beginning or finishing of a task.
  "Of the group, Max (Room’s Jacob Tremblay) is the most nominally mature, at least biologically speaking; unlike his childhood companions, he’s entered the early throes of puberty, and spends a lot of his waking hours pining, rather chastely, for a classmate (Millie Davis)."

verb

• (transitive) To cause (someone) to feel throes, as if in childbirth; to put in agony.
  "Pre-thee ſay on, / The ſetting of thine eye, and cheeke proclaime / A matter from thee; and a birth, indeed, / Which throwes thee much to yeeld."
• (intransitive) To feel throes; to struggle in extreme pain; to be in agony; to agonize.
  "[W]hile yet he gazed at the wonderful countenance, his memory began to throe and struggle."