Plank: Kumbhakāsana or Phālakāsana
I’m not sure which is the most common term (these are both new to me). I like kumbhakāsana, as there usually is a breath retention for some period of time in high plank. As part of Sūryanamaskāra, we inhale to shift forward from down dog into plank, retain the inhale in kumbhakāsana, and then exhale to lower through caturaṅga daṇḍāsana.