bottom

1 bottom /ˈbɑːtəm/ noun
plural bottoms
1 bottom
/ˈbɑːtəm/
noun
plural bottoms
Britannica Dictionary definition of BOTTOM
1 
a  [count] : the lowest part, point, or level of something — usually singular
b  [count] : the part of something that is below or under the other parts — usually singular
c  [count] : the lowest point or surface inside something : the part of something hollow that is furthest from the top — usually singular
d  [singular] chiefly British : the part of something that is furthest away
2 
[count] : the part of the body on which you sit : buttocks
3 
a  [singular] : a position of little power in a company or organization
b  [singular] : a low rank or position
c  [noncount] : the worst position, level, or condition
— see also rock bottom
4 
a  [singular] : the surface that is under a body of water
b  bottoms [plural] : the flat, low land along a river or stream : bottomland
5 
[count] : a piece of clothing that is worn on the lower part of the body — often plural — see color picture on this page
6 
[singular] : the second half of an inning in baseball
7 
[noncount] chiefly British : the lowest gear of a car

at bottom

chiefly British
: in reality : really

at the bottom of the pile

— see 1pile

be/lie at the bottom of

chiefly British
: to be the source or originator of (something)

bottoms up

informal
— used as a toast or to tell people to finish their drinks

from the bottom of your heart

— see heart

from top to bottom

— see 1top

get to the bottom of

: to find out the true reason for or cause of (something)

the bottom drops/falls out

◊ If the bottom drops/falls out of something, it suddenly fails or becomes unable to continue in a normal and effective way.

the bottom of the barrel

: the lowest possible condition, level, etc.

— bottomed

/ˈbɑːtəmd/ adjective
2 bottom /ˈbɑːtəm/ adjective
2 bottom
/ˈbɑːtəm/
adjective
Britannica Dictionary definition of BOTTOM
always used before a noun
1 
: in the lowest position
— see also bottom line
2 
: living at the lowest level of an ocean or lake

bet your bottom dollar

— see 2bet
3 bottom /ˈbɑːtəm/ verb
bottoms; bottomed; bottoming
3 bottom
/ˈbɑːtəm/
verb
bottoms; bottomed; bottoming
Britannica Dictionary definition of BOTTOM

bottom out

[phrasal verb]
: to reach a lowest or worst point usually before beginning to rise or improve