Verb
1. cause to open or to become open;
"Mary opened the car door"2. start to operate or function or cause to start operating or functioning;
"open a business"3. become open;
"The door opened"4. begin or set in action, of meetings, speeches, recitals, etc.;
"He opened the meeting with a long speech"5. spread out or open from a closed or folded state;
"open the map""spread your arms"6. make available;
"This opens up new possibilities"7. become available;
"an opportunity opened up"8. have an opening or passage or outlet;
"The bedrooms open into the hall"9. make the opening move;
"Kasparov opened with a standard opening"10. afford access to;
"the door opens to the patio""The French doors give onto a terrace"11. display the contents of a file or start an application as on a computer
Adjective
1. affording unobstructed entrance and exit; not shut or closed;
"an open door""they left the door open"2. affording free passage or access;
"open drains""the road is open to traffic""open ranks"3. with no protection or shield;
"the exposed northeast frontier""open to the weather""an open wound"4. open to or in view of all;
"an open protest""an open letter to the editor"5. used of mouth or eyes;
"keep your eyes open""his mouth slightly opened"6. not having been filled;
"the job is still open"7. accessible to all;
"open season""an open economy"8. not defended or capable of being defended;
"an open city""open to attack"9. (of textures) full of small openings or gaps;
"an open texture""a loose weave"10. having no protecting cover or enclosure;
"an open boat""an open fire""open sports cars"11. opened out;
"an open newspaper"12. of a set; containing points whose neighborhood consists of other points of the same set, or being the complement of an open set; of an interval; containing neither of its end points
13. not brought to a conclusion; subject to further thought;
"an open question""our position on this bill is still undecided""our lawsuit is still undetermined"14. not sealed or having been unsealed;
"the letter was already open""the opened package lay on the table"15. without undue constriction as from e.g. tenseness or inhibition;
"the clarity and resonance of an open tone""her natural and open response"16. relatively empty of and unobstructed by fences or hedges or headlands or shoals;
"in open country""the open countryside""open waters""on the open seas"17. open and observable; not secret or hidden;
"an overt lie""overt hostility""overt intelligence gathering"18. used of string or hole or pipe of instruments
19. not requiring union membership;
"an open shop employs nonunion workers"20. possibly accepting or permitting;
"a passage capable of misinterpretation""open to interpretation""an issue open to question""the time is fixed by the director and players and therefore subject to much variation"21. not secret;
"open plans""an open ballot"22. without any attempt at concealment; completely obvious;
"open disregard of the law""open family strife""open hostility""a blatant appeal to vanity""a blazing indiscretion"23. affording free passage or view;
"a clear view""a clear path to victory"24. lax in enforcing laws;
"an open town"25. openly straightforward and direct without reserve or secretiveness;
"his candid eyes""an open and trusting nature""a heart-to-heart talk"26. sincere and free of reserve in expression;
"Please be open with me"27. receptive to new ideas;
"an open mind""open to new ideas"28. ready for business;
"the stores are open"