noun
plural depths
a distance below a surface [count]
[count] :the distance from the front of something to the back - usually singular
[count] :an area that exists far below a surface or far inside something :a deep place or area - usually plural
[count] a very low or bad state or condition - usually plural
the worst part of something
[noncount] :the quality of being deep: such as
the quality of being strongly felt
the quality of being very bad or serious
the quality of being complete or thorough
the quality of being strong in color, taste, etc.
the quality of being low in sound
f US sports :the quality of having many good players on a team
in depth
in a thorough or complete way
out of your depth
also beyond your depth
dealing with a situation or subject that is too difficult for you
chiefly Brit :in water that is deeper than your height