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insistent; obstinate; persistent; tenacious
too rich (taste, etc.); fatty; heavy; greasy
彼のしつこい質問に困ってしまった。
I was troubled by his persistent questions.
しつこいセールスマンに何度も断った。
I refused the pushy salesman many times.
しつこく誘われて断り切れなかった。
I was persistently invited and couldn't refuse.