dawn on (you)

to suddenly understand something.

It finally dawned on him that she'd been joking and he was worried for no reason.

• in deep shit
• in demand
• in depth
• in detail
• in dire straits
• in dispute
• in dribs and drabs
• in due course
• in due time
• in earnest
• in eclipse
• in element
• in evidence
• in eyes
• in face
• in fact
• in favor of
• in favor of something
• in fits and starts
• in flagrante
• in flagrante delicto
• In for a penny.
• In for a penny, in for a pound.
• in force
• in for the kill