burgeon
Concise Oxford English Dictionary © 2008 Oxford University Press:
burgeon /ˈbəːdʒ(ə)n/
▶verb (often as adj. burgeoning) grow or increase rapidly.
– origin ME: from OFr. bourgeonner ‘put out buds’, from borjon ‘bud’, based on late L. burra ‘wool’.
'burgeon' also found in these Oxford entries:

