Callous describes someone hardened and unfeeling, showing no concern for others' suffering. Callow describes someone young, inexperienced, or naive. A callous remark is cruel; a callow mistake is simply the kind of error inexperience produces. The words look alike but describe almost opposite personalities.
The core difference
Callous means unfeeling or hard-hearted; callow means young and inexperienced.
- callous — showing no concern for the feelings or suffering of others; also, having thickened, hardened skin: she stayed callous towards her neighbour's complaints, dismissing them without a second thought.
- callow — immature, inexperienced, or naive: a callow graduate on his first day in the job.
How to tell them apart
Callous and callow both share a root sense of hardness, but they took different routes. Callous comes from Latin callosus, "thick-skinned," and kept that idea both literally, for hardened skin, and figuratively, for a person hardened against other people's feelings. Callow comes from an Old English word for bald or bare, and settled into meaning someone not yet toughened by experience — the opposite of hardened.
A handy memory trick: callous people have too much toughness, callow people have too little experience. If a description involves cruelty or a lack of empathy, reach for callous. If it involves youth, naivety, or being new to something, callow is the word you want.
