catch on

In addition to the idioms beginning with catch

• catch as catch can
• catch at
• catch a Tartar
• catch cold
• catch fire
• catch in the act
• catch it
• catch napping
• catch off guard
• catch on
• catch one’s breath
• catch one’s death (of cold)
• catch red-handed
• catch sight of
• catch someone’s eye
• catch some rays
• catch some z’s
• catch the drift
• catch up

also see:

• early bird catches the worm
• get (catch) the drift
• takes one to know one (a thief to catch a thief)

Also see undercaught.