Name for same-note legato without the pedal

Question

I am drawing a complete blank for the name of a particular technique for piano I learned a while ago, and I haven't the time to dig through my books to find it...

A connecting technique for playing unison notes legato without the pedal. The key is depressed for the first note, but instead of lifting the weight of the finger completely off the key to play the second note, leave the key just depressed enough to keep the damper off the strings to play the same note again mid-vibration.

Answer 1

Finger pedalling, or finger sustain. I've also heard it referred to as "sticky fingers".

If you switch fingers it would be part of finger substitution.