open

1 open /ˈoʊpən/ adjective
opener; openest
1 open
/ˈoʊpən/
adjective
opener; openest
Britannica Dictionary definition of OPEN
[or more open; most open]
1 
: not closed: such as
a  : not covering an opening
b  : having an opening that is not covered
2 
: not sealed or locked
3 
: allowing movement or travel : not blocked
4 
: able to be entered and used by customers, visitors, etc.
5 
: having parts that are spread apart instead of folded together or attached
6 
a  : not containing or surrounded by walls, fences, buildings, etc.
b  of a building or room : having few walls
7 
a  : including or allowing a particular group of people — usually + to
b  : including or allowing all people
8 
a  : available to be used
— often + to
b  of a job, position, etc. : not yet taken : available for someone to take or fill
9 
: happening or done in public so that people can participate or know what is being said or done
10 
: not hidden or secret
11 
: expressing thoughts and feelings in a direct and honest way
12 
: willing to listen to or accept different ideas or opinions
13 
a  : not having ended : not yet finished or decided
b  : allowing further comments or discussion
— see also open to debate at 1debate
14 
: able to be criticized, harmed, doubted, etc. — usually + to
15 
sports : not blocked or guarded by players from the other team
16 
computers — used to describe a file, document, etc., that is being used
17 
— used to describe a microphone that is turned on
18 
of fabric : having large openings or spaces between threads

keep your eyes open

— see 1eye

with your/both eyes open

— see 1eye
2 open /ˈoʊpən/ verb
opens; opened; opening
2 open
/ˈoʊpən/
verb
opens; opened; opening
Britannica Dictionary definition of OPEN
1 
a  [+ object] : to move (a door, window, etc.) so that an opening is no longer covered
b  [no object] : to move and no longer cover an opening
◊ The opposite of open is close in every sense except sense 10.
2 
[+ object] : to cause (something) to no longer be covered, sealed, or blocked
3 
: to separate the parts or edges of (something)
[+ object]
[no object]
4 
: to make a hole or opening in (something)
[+ object]
[no object]
5 
: to allow (a park, road, etc.) to be used
[+ object]
[no object]
6 
a  : to begin the regular services or activities of (a business, school, etc.)
[+ object]
[no object]
b  : to begin the activities or services of (a business, school, etc.) for the first time
[+ object]
[no object]
7 
: to begin (something)
[+ object]
[no object]
8 
[+ object] : to begin keeping money in (an account at a bank)
9 
[+ object] computers : to begin to use (a file, document, or program) on a computer
10 
always followed by an adverb or preposition, [no object] : to allow movement or passage through a doorway or other opening
— often + out
11 
[no object] : to have a specified price or be at a specified level at the beginning of the day

open doors for

: to give special opportunities to (someone)

open fire

: to begin shooting

open for

[phrasal verb]
open for (someone or something)
: to perform before (the main performer at a concert, show, etc.)

open out

[phrasal verb] British
: to become less shy and speak more freely
— see also 2open 10 (above)

open someone's eyes

— see 1eye

open the door

or open the way
: to make (something) easier or more likely to happen — often + for or to

open to

[phrasal verb]
1 
open (something) to (someone or something) : to allow (a particular group of people) to enter, use, or participate in (something)
2 
open (someone or something) to (something) : to cause or allow (someone or something) to be affected by (something bad, such as criticism)

open up

[phrasal verb]
1 
: to become less shy and speak more freely
2 
: to begin shooting
3 
— used to demand that someone who is inside a room, building, etc., let you in
4 
open up or open up (something) or open (something) up
a  : to become or cause (something) to become available or possible
b  : to become or cause (something) to become wider or less crowded
c  : to develop or cause (something) to develop

open your bowels

— see bowel

open your doors

— see door

open your heart

— see heart

open your mind

: to become able to understand different ideas or ways of thinking
— often + to

— openable

/ˈoʊpənəbəl/ adjective
3 open /ˈoʊpən/ noun
plural opens
3 open
/ˈoʊpən/
noun
plural opens
Britannica Dictionary definition of OPEN
1 
[count] : a competition (such as a major golf tournament or tennis tournament) that allows both professionals and amateurs to participate — usually used in names
2 
the open
a  : an area or place without walls, barriers, etc. : an area or place that is not covered or enclosed — used in the phrase (out) in/into the open
b  : a situation in which something (such as a feeling) is no longer hidden or kept secret — used in the phrase (out) in/into the open