dưới thời kỳ này 
during this time, period [ dưới ] : below, under
[ thời ] : time(s), era
[ kỳ ] : (1) term, period, session; issue, number (of a periodical); (2) strange, odd, eccentric; (3) until; (4) chess; (5) flag; (6) to request, hope for; (7) to rub
[ này ] : here; this, these; (expression) by the way, say
Most Common Compounds Set 1:
Most Common Compounds Set 2 :