to fail completely in an embarrassing way
провалиться полностью в неловкой ситуации (provalit'sya polnost'yu v nelovkoy situatsii)
"He fell flat on his face during his first business attempt."
"Он провалился на своей первой попытке бизнеса." (On provalilsya na svoey pervoy popytke biznesa.)
to keep something secret
to fulfill your part of an agreement or duty
to trust or believe in someone’s ability
exactly at the right moment
to use the same tactics as one’s opponent
to make someone very annoyed or angry