4 across
Physicist
from
college
welcomed
by
board
(6)
Physicist from college welcomed by board (6)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
The definition is Physicist — that's Max Planck you're after. Take C (the abbreviation for college) and have it welcomed by (popped inside) PLANK (a board), and you get PLAN-C-K.