lower
verb
°To let descend by its own weight, as something suspended; to let down; as, to lower a bucket into a well; to lower a sail of a boat; sometimes, to pull down; as, to lower a flag.
°To reduce the height of; as, to lower a fence or wall; to lower a chimney or turret.
synonyms: shorten, reduce, turn down, cut more» , die off, drop, fall, fall off, shrink, lessen
middle
noun
°A centre, midpoint.
"The middle of a circle is the point which has the same distance to every point of circle."
°The part between the beginning and the end.
adjective
°Being in the middle or in-between; as middle point, middle name, Middle English, Middle Ages, middle weight, etc.
°Central to.
synonyms: centre, center, midpoint, midst
upper
noun
°That which is higher, contrasted with the lower.
"As the restless sleeper here, I'll take the lower berth. You take the upper."
°(shoemaking) The piece of leather, etc., that forms the top part of a shoe above the sole.
adjective
°At a higher level, rank or position.
°Situated on higher ground, further inland, or more northerly.