absentminded

WordReference Random House Learner's Dictionary of American English © 2025

ˈab•sent-ˈmind•ed or ˈab•sent•ˈmind•ed, adj. 

1. preoccupied with one's thoughts so as to be unaware or forgetful of other matters.

ab•sent--mind•ed•ly, adv. 
ab•sent--mind•ed•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2025

ab•sent-mind•ed  (ab′sənt mīn′did), adj. 

1. so lost in thought that one does not realize what one is doing, what is happening, etc.;
   preoccupied to the extent of being unaware of one's immediate surroundings.

Also, ab′sent•mind′ed. 

• 1850–55

ab′sent-mind′ed•ly, adv. 
ab′sent-mind′ed•ness, n. 
Synonyms

withdrawn, musing, daydreaming, dreamy, forgetful, distracted. Absent-minded, abstracted, oblivious all mean inattentive to immediate surroundings. Absent-minded suggests an unintentional wandering of the mind from the present:
an absent-minded committee member.
Abstracted implies that the mind has been drawn away from the immediate present by reflection upon some engrossing subject:
an abstracted air.
Oblivious implies absorption in some thought that causes one to be completely forgetful of or unaware of one's surroundings:
oblivious of danger.

Antonyms

attentive, alert, heedful, observant.

Collins Concise English Dictionary © HarperCollins Publishers::

absent-minded adjective

1. preoccupied; forgetful; inattentive

ˌabsent-ˈmindedly adverb

ˌabsent-ˈmindedness noun