1 LOWEST PART the lowest part of something: the bottom: From the bottom the skyscraper looked as if it touched the clouds.(+ of): Hold the bottom of the pole and keep it upright. | at the bottom: Go downstairs and wait for me at the bottom. | at the bottom of Sign your name at the bottom of the page -opposite top 1 (1)2 SEA/RIVER the ground under a sea, river etc, or the flat land in a valley: the bottom: the sea bottom(+ of): The bottom of the pool is very slippery. | at/on the bottom of sth: A body was found at the bottom of the canal.3 LOWEST SIDE the flat surface on the lowest side of an object: the bottom: Take the price tag off the bottom.(+ of): You have chewing gum stuck to the bottom of your shoe.4 CUP/BOX ETC the lowest inner surface of something such as a cup or container: the bottom: Yuk, this cup's got mould in the bottom.(+ of): The flour is at the bottom of the cupboard.5 LOWEST POSITION the lowest position in an organization or company, or on a list etc: the bottom: The team is at the bottom of the league. | start at the bottom: Higgins started at the bottom and worked his way up to managing director. | the bottom of the ladder/pile (=the lowest position in society, an organization etc)-opposite top 1 (3)6 the bottom of a road/garden etc especially BrE the part of a road, area of land etc that is furthest from where you are: There's a shop at the bottom of the street.7 BODY (C) the part of your body that you sit on; buttocks: I just sat on my bottom and slid down.8 CLOTHES (C) also bottoms the part of a set of clothes that you wear on the lower part of your body: bikini bottom | pyjama bottoms9 get to the bottom of to find out the cause of a problem or situation: I'm going to get to the bottom of this!10 be at the bottom of to be the basic cause of a problem or situation: I'm sure Carrie's disturbed childhood is at the bottom of her current problems.11 hit rock bottom/be at rock bottom to reach a very low level, or be in a very bad situation: Morale has hit rock bottom. | We bought the house when prices were at rock bottom.12 from the bottom of your heart in a very sincere way: Thank you from the bottom of my heart.13 big-bottomed/round-bottomed etc having a bottom or base that is big, round etc14 the bottom dropped out of sb's world used to say that something very bad suddenly happened to someone15 the bottom drops out of the market used to say that people stop buying a particular product16 bottoms up! spoken used to tell someone to enjoy or finish their alcoholic drink17 bottom gear the lowest gear 1 (1) of a vehicle18 SHIP (C) the part of a ship that is below water19 at bottom the way a person or situation really is, although they may seem different: She's a good, kind person at bottom.-compare top 2, -see also: you can bet your bottom dollar bet 1 (2), knock the bottom out of knock 1 (17), from top to bottom top 1 (19) 2 adjective (only before noun)1 in the lowest place or position: The records are kept on the bottom shelf. | the bottom right hand corner of the page2 the least important, successful etc: Tim is in the bottom 10% of his class.3 especially BrE in the place furthest away from where you are: Most of the sheep were grazing in the bottom field.3 verb bottom out phrasal verb (I) if a situation, price etc bottoms out, it stops getting worse or lower, usually before improving again: The market price of oil got as low as $10 a barrel before it finally bottomed out.
Longman dictionary of contemporary English. 2004.