absent-minded
adjective
[ ˌabs(ə)ntˈmʌɪndɪd ]
• having or showing a forgetful or inattentive disposition.
• "an absent-minded smile"
Similar:
forgetful,
distracted,
preoccupied,
inattentive,
vague,
absorbed,
abstracted,
unheeding,
oblivious,
distrait,
in a brown study,
wool-gathering,
lost in thought,
pensive,
thoughtful,
brooding,
scatterbrained,
miles away,
absence of mind
• failure to concentrate on or remember what one is doing.
• "his reply conveyed his absence of mind"