I didn't catch on at first, but now I understand.
catch on
idiomTo understand; to begin to understand; to realize.
Origin
disputed originFrom catch (verb) + on (preposition).
It took her a while to catch on that he was joking.
Watching the subtle shift in his expression, she finally began to catch on that something was terribly wrong.
- 01
catch a body
to kill, to murder
- 02
catch a break
To experience the minimal amount of good luck or a favorable outcome.
- 03
catch a case
To be infected with a disease; used with of.
- 04
catch a cold
To contract a cold.
- 05
catch a date
Of a prostitute, to secure a client who is willing to pay for services.
- 06
catch a fade
To get knocked out (struck and rendered unconscious).
- 07
catch a falling knife
To buy a financial instrument whose price is falling rapidly.
- 08
catch a packet
To be fired upon.
Last updated April 17, 2026