adj

• (not comparable) Being away from a place; withdrawn from a place; existing but not present; (sometimes) missing.
  "Owing to his own illness and then his family's, Ramzi has often been absent from class this month. We will help him catch up with his studies."
• (not comparable) Not existing.
  "The body part was rudimentary or absent in 1% of specimens."
• (comparable) Inattentive to what is passing; absent-minded; preoccupied.
  "Tom was there, but he seemed absent and withdrawn. Normally he is quite present [= engaged] during a meeting."

noun

• (with definite article) Something absent, especially absent people collectively; those who were or are not there.
  "The Applause he met with exceeds all belief of the Absent."
• (obsolete, Scotland) An absentee; a person who is not there.

verb

• (reflexive) To keep (oneself) away.
  "Most of the men are retired, jobless, or have otherwise temporarily absented themselves from the workplace."
• (transitive, archaic) To keep (someone) away.
  "Go; for thy stay, not free, absents thee more;"
• (intransitive, obsolete) Stay away; withdraw.
  "The iron rule of the plantation, always passionately and violently enforced in that neighborhood, makes flogging the penalty of failing to be in the field before sunrise in the morning, unless special permission be given to the absenting slave."
• (transitive, rare) Leave.