זיכרונו לברכה

Literally “memory-of-him for-blessing”, hence roughly “his memory is a blessing” or “may his memory be a blessing”.

⁧זיכרונו לברכה⁩ • (zikhronó liv'rakhá)

1. Of blessed memory, may he rest in peace; used after a reference to a deceased man or boy.

• In writing, this term is usually abbreviated ⁧ז״ל⁩ (Z.L.).
• This is the masculine singular form; the feminine singular is ⁧זיכרונה לברכה⁩ (zikhroná liv'rakhá), the masculine plural is ⁧זיכרונם לברכה⁩ (zikhronám liv'rakhá), and the feminine plural is ⁧זיכרונן לברכה⁩ (zikhronán liv'rakhá).