Synonyms of the word

thoughtless

• adj. Marked by or showing lack of due thought or care; careless.
• adj. Inconsiderate, inattentive.
• adj. Lacking thought or consideration.

careless

• adj. (archaic) Free from care; unworried, without anxiety.
• adj. Not concerned or worried (about).
• adj. Not giving sufficient attention or thought, especially concerning the avoidance of harm or mistakes.

deaf

• adj. Unable to hear, or only partially able to hear.
• adj. Unwilling to listen or be persuaded; determinedly inattentive; regardless.
• adj. Obscurely heard; stifled; deadened.
• adj. (obsolete, Britain, dialect) Decayed; tasteless; dead.
• n. A deaf person.
• n. (with "the") Those who are deaf, taken as a group.
• v. (obsolete, transitive) To deafen.

heedless

• adj. Unaware, without noticing.

inconsiderate

• adj. Not considerate of others, thoughtless.
• adj. (obsolete) inconsiderable.

indifferent

• adj. Not caring or concerned; uninterested, apathetic.
• adj. Mediocre, usually used negatively in modern usage.
• adj. Having no preference or bias, being impartial.
• adj. Not making a difference; without significance or importance.
• adj. (mechanics) Being in the state of neutral equilibrium.
• adv. (obsolete) To some extent, in some degree (intermediate between very and not at all); moderately, tolerably,…

regardless

• adj. Having no regard; heedless; careless.
• adv. Without attention to warnings or indications of bad consequences.
• prep. Paying no attention to; regardless of.

uncaring

• adj. Characterized by a lack of care; not caring.

unconsidered

• adj. Not considered.

unheeding

• adj. Showing disregard.

unreflective

• adj. Not reflective; thoughtless.

unthinking

• adj. Without proper thought; thoughtless.
• adj. Showing no regard; careless or unconcerned.
• v. present participle of unthink.

unthoughtful

• adj. inconsiderate of other's feelings.
• adj. unplanned or unthinking.