noun

• (countable and uncountable) An ache or bodily suffering, or an instance of this; an unpleasant sensation, resulting from a derangement of functions, disease, or injury by violence; hurt.
  "The greatest difficulty lies in treating patients with chronic pain."
• (countable and uncountable) An ache or bodily suffering, or an instance of this; an unpleasant sensation, resulting from a derangement of functions, disease, or injury by violence; hurt.
  "When the pains are every five minutes and quite strong or the cervix is five cm. dilated along with regular and strong pains, the mother is given a block anesthesia of 1 cc. of 1:200 nupercaine, 1 cc. of 10 per cent dextrose with .05 cc. of 1:1000 adrenalin."
• (uncountable) The condition or fact of suffering or anguish especially mental, as opposed to pleasure; torment; distress
  "In the final analysis, pain is a fact of life."
• (countable, from pain in the neck) An annoying person or thing.
  "Your mother is a right pain."

verb

• (transitive) To hurt; to put to bodily uneasiness or anguish; to afflict with uneasy sensations of any degree of intensity; to torment; to torture.
  "The wound pained him."
• (transitive) To render uneasy in mind; to disquiet; to distress; to grieve.
  "It pains me to say that I must let you go."
• (transitive, obsolete) To inflict suffering upon as a penalty; to punish.
• (intransitive, India) To feel pain; to hurt.
  "Please help me, I am paining hard."

noun

• (obsolete, cooking) Any of various breads stuffed with a filling.
  "gammon pain; Spanish pain"