The opposite position of sit is "stand."
Standing, NOT FALLING, balanced, etc....
Blend in
Blend in
The opposite of up is down. So, opposite of the opposite of up is up itself.
stand still
...stand
of Stand, imp. & p. p. of Stand.
If someone can't stand something, that person hates or abhors it. The opposite would be adores, loves, or the like.
run, sprint
The minus sign.
stand