Put your feet up, relax and let Tim Bowen entertain you with this lively discussion on idioms involving feet.
The word literally is often misused both in speech and writing. If we say that something happened literally, then we mean that it actually did happen and that our statement is not exaggerated in any way. So, if there were literally thousands of people at the meeting, the statement means just that and not simply that there were a lot of people there. An often quoted example of the misuse of literally is 'Every time he opens his mouth he literally puts his foot in it'. Well, no he doesn't - unless he happens to be a contortionist that is. The use of literally here removes the idiomatic meaning from the idiom to put one’s foot in it (to accidentally say something that is embarrassing or that upsets or annoys someone). It is difficult to imagine a situation in which you were so busy that you were literally rushed off your feet (very busy) and likewise literally having one foot in the grave (being very ill and likely to die soon) would present quite a graphic image. As a verb, to foot means to kick, as in to foot a ball across the field. Therefore, if you literally foot the bill it means you kick the bill rather than paying it (much more likely).
If you have cold feet about something (feel nervous about something you have planned or agreed to do), your nervousness would probably manifest itself in other ways than in the temperature of your feet, and if your children are under your feet (in the way and annoying you), they are unlikely to be literally under your feet. But if you put your feet up (sit down and relax), this might conceivably be with your feet raised off the ground. Similarly, if you are back on your feet (well again) after an illness, this could mean that you are once again able to stand up. Most of the time, however, it is advisable to avoid the use of literally, especially with idioms, otherwise you may inadvertently put your foot in your mouth (accidentally say something inappropriate) and end up sounding silly. Otherwise, you might repeat the error of the English football manager who famously said of a player 'He literally has two left feet'.