callous

As adjectives the difference between callous and undefined

is that callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others while undefined is lacking a definition or value.

As adjectives the difference between reserved and callous

is that reserved is slow to reveal emotion or opinions while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

As a verb reserved

is past tense of reserve.

Firm is a related term of callous.

As adjectives the difference between firm and callous

is that firm is steadfast, secure, hard (in position) while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

As a noun firm

is (uk|business) a business partnership; the name under which it trades.

As a verb firm

is to make firm or strong; fix securely.

As adjectives the difference between callous and drastic

is that callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others while drastic is extreme; severe.

As adjectives the difference between callous and rigid

is that callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others while rigid is rigid.

As adjectives the difference between melancholy and callous

is that melancholy is affected with great sadness or depression while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

As a noun melancholy

is (historical) black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.

Stupid is a related term of callous.

As adjectives the difference between stupid and callous

is that stupid is lacking in intelligence or exhibiting the quality of having been done by someone lacking in intelligence while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

As an adverb stupid

is (slang|dated) extremely.

As a noun stupid

is a stupid person; a fool.

Inexorable is a related term of callous.

As adjectives the difference between inexorable and callous

is that inexorable is unable to be persuaded; relentless; unrelenting while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

Severe is a related term of callous.

As adjectives the difference between severe and callous

is that severe is severe, harsh while callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others.

As adjectives the difference between callous and calamitous

is that callous is emotionally hardened; unfeeling and indifferent to the suffering/feelings of others while calamitous is concerning or involving calamity, disastrous.