זיכרונו לברכה

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

Interjection

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

Usage notes

 * In writing, this term is usually abbreviated.
 * This is the masculine singular form; the feminine singular is, the masculine plural is , and the feminine plural is.