低估

underrate; underestimate; undervalue; sell short; discount; downgrade; underestimation; conservative

困难

difficulty; problem; hardship; trouble; bother; rub; strives; pitfall; distress; straits; predicament; adversity; difficult; hard; short; painful; stiff; challenging; tough; arduous; onerous; ill; painfully; make difficult; be in difficulty; be in a tight spot; be in dire straits; be in a bind; be in a jam; in a mess; with difficulty; hard going