to knock out: to make unconscious; to impress or attract greatlyThis idiom can be made into the noun from knockout for both definitions. Examples of TO KNOCK OUT The prizefighter knocked out his opponent with one punch. The stone hit her on the head and knocked her out for a few minutes.  

to go up to: to approach (also: to come up to, to walk up to, to run up to, to drive up to, etc.)The related forms have the same meaning, but the type of movement isdifferent. Examples of TO GO UP TO A woman came up to the pair, and Calipari expected her to ask for…

to put away: to remove from slight, to put in the proper place Examples of PUT AWAY The kid refused to put away his toys and so he didn’t get his allowance. He wanted to put away the leftovers right away, so they wouldn’t spoil.

to step down: to retire or leave a top position, to resign Examples of TO STEP DOWN Next May the principal will step down after thirty-five years of service to the school. The angry shareholders wanted the company president to step down because of the stock scandal.

to keep up with: to maintain the same speed or rate as Examples of TO KEEP UP WITH Olivia tirelessly worked her garden because she wanted her yard to keep up with her neighbors’. The inexperienced runner wasn’t able to keep up with the champions, even though he tried really hard.

on the other hand: however, in contrast Examples of ON THE OTHER HAND On the other hand, registered voters may participate in any primary they choose. Kidney inflammation, on the other hand, is rare, but no treatment exists for it.