harmless

adjective

harm·​less ˈhärm-ləs 

1

: free from harm, liability, or loss

2

: lacking capacity or intent to injure : innocuous

a harmless joke

harmlessly adverb

harmlessness noun

Synonyms of harmless

• benign
• safe
• innocent
• innocuous
• inoffensive
• healthy

Examples of harmless in a Sentence

His ideas seem harmless enough.

We're just having a bit of harmless fun.

It was just a harmless joke.

Recent Examples on the Web

Too little, however, can cause otherwise harmless particles to dry out and become airborne irritants. —Bestreviews, Chicago Tribune, 17 Mar. 2026

These giant, but harmless, creatures are attracted by the lights, which in turn attract the plankton the rays dine on. —Ben Davidson, Mercury News, 16 Mar. 2026

Some parasites are harmless, even for people with weakened immune systems. —Sarah Boden, NPR, 16 Mar. 2026

Grease and oil might look harmless, but grease has the potential to congeal and harden, while leftover oil can coat your pipes and cause other things to get stuck. —Alexandra Kelly, Martha Stewart, 15 Mar. 2026

Word History

First Known Use

13th century, in the meaning defined at sense 1

Kids Definition

harmless

adjective

harm·​less ˈhärm-ləs 

1

: free from harm

2

: unable to harm

harmlessly adverb

harmlessness noun

Legal Definition

harmless

adjective

harm·​less

1

: free from harm, liability, or loss

—often used in the phrase to hold harmless see also hold harmless

2

: lacking capacity or intent to injure

harmlessly adverb

harmlessness noun